1 | /* |
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2 | Copyright (C) 2015 |
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3 | Alejandro Mujica (amujica en cenditel.gob.ve) |
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4 | José Ángel Contreras (jancontreras en cenditel.gob.ve) |
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5 | Antonio Araujo (aaraujo en cenditel.gob.ve) |
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6 | Pedro Buitrago (pbuitrago en cenditel.gob.ve) |
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7 | |
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8 | CENDITEL Fundación Centro Nacional de Desarrollo e Investigación en |
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9 | Tecnologías Libres |
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10 | |
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11 | Este programa es software libre; Usted puede usarlo bajo los términos de la |
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12 | licencia de software GPL versión 2.0 de la Free Software Foundation. |
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13 | |
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14 | Este programa se distribuye con la esperanza de que sea útil, pero SIN |
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15 | NINGUNA GARANTÍA; tampoco las implícitas garantías de MERCANTILIDAD o |
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16 | ADECUACIÓN A UN PROPÓSITO PARTICULAR. |
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17 | Consulte la licencia GPL para más detalles. Usted debe recibir una copia |
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18 | de la GPL junto con este programa; si no, escriba a la Free Software |
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19 | Foundation Inc. 51 Franklin Street,5 Piso, Boston, MA 02110-1301, USA. |
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20 | */ |
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21 | |
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22 | /* |
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23 | Este archivo contiene la definición e implementación de una clase tipo |
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24 | plantilla para representar polinomios. |
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25 | |
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26 | Creado por: Alejandro J. Mujica |
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27 | Fecha de creación: |
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28 | */ |
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29 | |
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30 | |
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31 | # ifndef POLYNOMIAL_H |
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32 | # define POLYNOMIAL_H |
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33 | |
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34 | # include <stdexcept> |
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35 | # include <sstream> |
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36 | # include <vector> |
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37 | # include <limits> |
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38 | |
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39 | # include<iostream> |
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40 | |
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41 | /** |
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42 | * Plantilla para representar polinomios con tipo de coeficientes paramétrico. |
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43 | * |
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44 | * @param Number_Type El tipo de dato para los coeficientes. Debe pertenecer |
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45 | * a los tipos aritméticos de la biblioteca estándar de C++. |
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46 | * Por omisión es de tipo double. |
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47 | * |
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48 | * @author Alejandro Mujica (amujica en cenditel punto gob punto ve). |
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49 | * @author José Angel Contreras (jancontreras en cenditel punto gob punto ve). |
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50 | */ |
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51 | template <typename Number_Type = double> |
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52 | class Polynomial |
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53 | { |
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54 | public: |
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55 | /// Tipo de conjunto para el polinomio. |
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56 | typedef std::vector<Number_Type> pol_t; |
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57 | /// Tipo de número para el grado. |
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58 | typedef typename pol_t::size_type degree_t; |
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59 | /// Tipo de número para los coeficientes. |
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60 | typedef typename pol_t::value_type number_t; |
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61 | |
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62 | private: |
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63 | degree_t deg; |
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64 | pol_t pol; |
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65 | |
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66 | public: |
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67 | /// Construcción de un polinomio dado un grado. |
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68 | Polynomial(const degree_t & _deg = degree_t(0)); |
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69 | |
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70 | /// Construcción por medio de una lista de inicialización. |
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71 | Polynomial(const std::initializer_list<number_t> &); |
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72 | |
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73 | /// Constructor copia |
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74 | Polynomial(const Polynomial &); |
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75 | |
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76 | /// Constructor de movimiento (move semantic) |
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77 | Polynomial(Polynomial &&); |
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78 | |
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79 | /// Retorna el grado del polinomio. |
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80 | const degree_t & degree() const |
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81 | { |
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82 | return deg; |
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83 | } |
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84 | |
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85 | /** |
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86 | * Retorna el coeficiente de la posición dada. |
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87 | * |
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88 | * @param exp Grado del coeficiente deseado. |
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89 | * @return Coeficiente de la posición dada. |
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90 | * @throw overflow_error si el exponente es mayor que el grado del polinomio. |
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91 | */ |
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92 | const number_t & get_coefficient(const degree_t & exp) const |
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93 | { |
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94 | if (exp > deg) |
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95 | throw std::overflow_error("exp is greater than polynomial degree"); |
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96 | |
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97 | return pol.at(deg - exp); |
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98 | } |
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99 | |
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100 | /** |
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101 | * Asigna valor al coeficiente de la posición dada. |
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102 | * |
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103 | * @param exp Grado del coeficiente deseado. |
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104 | * @param value Valor que se asignará al coeficiente. |
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105 | * @throw overflow_error si el exponente es mayor que el grado del polinomio. |
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106 | */ |
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107 | void set_coefficient(const degree_t & exp, const number_t & value) |
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108 | { |
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109 | if (exp > deg) |
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110 | throw std::overflow_error("exp is greater than polynomial degree"); |
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111 | |
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112 | pol.at(deg - exp) = value; |
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113 | } |
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114 | |
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115 | /// Determina si el polinomio es nulo. |
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116 | bool is_null() const; |
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117 | |
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118 | bool operator ! () const; |
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119 | |
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120 | Polynomial operator + (const Polynomial &); |
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121 | |
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122 | Polynomial & operator += (const Polynomial &); |
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123 | |
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124 | Polynomial operator - (const Polynomial &); |
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125 | |
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126 | Polynomial & operator -= (const Polynomial &); |
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127 | |
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128 | Polynomial operator * (const Polynomial &); |
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129 | |
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130 | Polynomial operator / (const Polynomial &); |
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131 | |
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132 | Polynomial operator % (const Polynomial &); |
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133 | |
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134 | Polynomial & operator = (const Polynomial &); |
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135 | |
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136 | Polynomial & operator = (Polynomial &&); |
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137 | |
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138 | bool operator == (const Polynomial &) const; |
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139 | |
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140 | bool operator != (const Polynomial &) const; |
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141 | |
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142 | /// Retorna una representación del polinomio en cadena. |
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143 | std::string to_string(const char & var = 'x'); |
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144 | }; |
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145 | |
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146 | /** |
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147 | * Constructor que funge de paramétrico y por omisión al mismo tiempo. |
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148 | * |
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149 | * @param _deg Grado del polinomio. Por omisión es 0. |
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150 | */ |
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151 | template <typename Number_Type> |
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152 | Polynomial<Number_Type>::Polynomial(const Polynomial::degree_t & _deg) |
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153 | : deg(_deg), pol(deg + degree_t(1), number_t(0)) |
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154 | { |
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155 | // Empty |
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156 | } |
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157 | |
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158 | /** |
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159 | * Construye un polinomio dada una lista de inicialización. |
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160 | * |
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161 | * Para inicializar el polinomio se deben pasar los valores de los coeficientes |
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162 | * encerrados por llaves y separados por coma (,). Debe escribirse el polinomio |
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163 | * completo. |
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164 | * Por ejemplo, si se quiere construir el polinomio |
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165 | * p = 1x^5 + 2x^4 + 3x^3 + 4x^2 + 5x + 6 |
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166 | * |
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167 | * La instanciación debe realizarse de la siguiente manera: |
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168 | * <code>Polynomial<> p = { 1, 2, 3, 4, 5, 6 };</code> |
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169 | * |
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170 | * @param l Lista de inicialización del polinomio. |
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171 | */ |
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172 | template <typename Number_Type> |
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173 | Polynomial<Number_Type>::Polynomial(const std::initializer_list<number_t> & l) |
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174 | : deg(degree_t(l.size()) - degree_t(1)), pol(l) |
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175 | { |
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176 | // Empty |
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177 | } |
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178 | |
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179 | template <typename Number_Type> |
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180 | Polynomial<Number_Type>::Polynomial(const Polynomial & p) |
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181 | : deg(p.deg), pol(p.pol) |
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182 | { |
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183 | // Empty |
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184 | } |
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185 | |
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186 | template <typename Number_Type> |
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187 | Polynomial<Number_Type>::Polynomial(Polynomial && p) |
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188 | : deg(degree_t(0)), pol(deg + degree_t(1), number_t(0)) |
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189 | { |
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190 | std::swap(deg, p.deg); |
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191 | std::swap(pol, p.pol); |
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192 | } |
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193 | |
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194 | |
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195 | /** |
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196 | * Determina si un polinomio es nulo. |
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197 | * Un polinomio es nulo si todos sus coeficientes son cero. |
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198 | * |
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199 | * @return <code>true</code> si el polinomio es nulo y <code>false</code> en |
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200 | * caso contrario. |
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201 | */ |
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202 | template <typename Number_Type> |
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203 | bool Polynomial<Number_Type>::is_null() const |
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204 | { |
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205 | for (const number_t & c : pol) |
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206 | if (c != number_t(0)) |
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207 | return false; |
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208 | return true; |
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209 | } |
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210 | |
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211 | template <typename Number_Type> |
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212 | bool Polynomial<Number_Type>::operator ! () const |
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213 | { |
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214 | return is_null(); |
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215 | } |
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216 | |
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217 | template <typename Number_Type> |
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218 | Polynomial<Number_Type> |
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219 | Polynomial<Number_Type>::operator + (const Polynomial & p) |
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220 | { |
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221 | const degree_t & min_degree = std::min(deg, p.deg); |
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222 | const degree_t & max_degree = std::max(deg, p.deg); |
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223 | |
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224 | Polynomial ret(max_degree); |
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225 | |
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226 | for (degree_t i = degree_t(0); i <= min_degree; ++i) |
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227 | ret.set_coefficient(i, get_coefficient(i) + p.get_coefficient(i)); |
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228 | |
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229 | const Polynomial & max_degree_pol = deg > p.deg ? *this : p; |
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230 | |
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231 | for (degree_t i = min_degree + degree_t(1); i <= max_degree; ++i) |
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232 | ret.set_coefficient(i, max_degree_pol.get_coefficient(i)); |
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233 | |
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234 | return ret; |
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235 | } |
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236 | |
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237 | template <typename Number_Type> |
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238 | Polynomial<Number_Type> & |
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239 | Polynomial<Number_Type>::operator += (const Polynomial & p) |
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240 | { |
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241 | *this = *this + p; |
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242 | return *this; |
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243 | } |
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244 | |
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245 | template <typename Number_Type> |
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246 | Polynomial<Number_Type> |
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247 | Polynomial<Number_Type>::operator - (const Polynomial & p) |
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248 | { |
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249 | const degree_t & min_degree = std::min(deg, p.deg); |
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250 | const degree_t & max_degree = std::max(deg, p.deg); |
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251 | |
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252 | Polynomial ret(max_degree); |
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253 | |
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254 | for (degree_t i = degree_t(0); i <= min_degree; ++i) |
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255 | ret.set_coefficient(i, get_coefficient(i) - p.get_coefficient(i)); |
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256 | |
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257 | Polynomial & max_degree_pol = deg > p.deg ? *this : p; |
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258 | |
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259 | char sign = &max_degree_pol == this ? 1 : -1; |
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260 | |
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261 | for (degree_t i = min_degree + degree_t(1); i <= max_degree; ++i) |
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262 | ret.set_coefficient(i, sign * max_degree_pol.get_coefficient(i)); |
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263 | |
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264 | return ret; |
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265 | } |
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266 | |
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267 | template <typename Number_Type> |
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268 | Polynomial<Number_Type> & |
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269 | Polynomial<Number_Type>::operator -= (const Polynomial & p) |
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270 | { |
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271 | *this = *this - p; |
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272 | return *this; |
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273 | } |
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274 | |
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275 | template <typename Number_Type> |
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276 | Polynomial<Number_Type> |
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277 | Polynomial<Number_Type>::operator * (const Polynomial & p) |
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278 | { |
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279 | Polynomial ret(deg + p.deg); |
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280 | |
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281 | for (degree_t i = degree_t(0); i <= deg; ++i) |
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282 | for (degree_t j = degree_t(0); j < p.deg; ++j) |
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283 | ret.set_coefficient(i + j, |
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284 | ret.get_coefficient(i + j) + get_coefficient(i) * p.get_coefficient(j)); |
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285 | |
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286 | |
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287 | return ret; |
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288 | } |
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289 | |
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290 | template <typename Number_Type> |
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291 | Polynomial<Number_Type> |
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292 | Polynomial<Number_Type>::operator / (const Polynomial & p) |
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293 | { |
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294 | if (p.is_null()) |
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295 | throw std::logic_error("Polynomial devision by 0"); |
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296 | |
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297 | if (p.deg > deg) |
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298 | return Polynomial(); |
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299 | |
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300 | Polynomial ret(deg - p.deg); |
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301 | |
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302 | number_t inv = number_t(0); |
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303 | |
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304 | if (p.deg > 0) |
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305 | { |
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306 | Polynomial tmp = *this; |
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307 | |
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308 | degree_t last = p.deg; |
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309 | |
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310 | while (last > degree_t(0) and p.get_coefficient(last) == number_t(0)) |
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311 | --last; |
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312 | |
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313 | inv = number_t(1) / p.get_coefficient(last); |
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314 | |
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315 | for (degree_t i = tmp.deg; i >= p.deg; --i) |
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316 | { |
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317 | ret.set_coefficient(i - p.deg, tmp.get_coefficient(i) * inv); |
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318 | |
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319 | for (degree_t j = degree_t(0); j <= p.deg; ++j) |
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320 | tmp.set_coefficient(i - j, |
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321 | tmp.get_coefficient(i - j) - p.get_coefficient(p.deg - j) * |
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322 | ret.get_coefficient(i - p.deg)); |
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323 | } |
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324 | |
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325 | return ret; |
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326 | } |
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327 | |
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328 | degree_t first = degree_t(0); |
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329 | |
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330 | while (first <= p.deg and p.get_coefficient(first) == number_t(0)) |
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331 | ++first; |
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332 | |
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333 | inv = number_t(1) / p.get_coefficient(first); |
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334 | |
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335 | for (number_t & c : ret.pol) |
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336 | c *= inv; |
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337 | |
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338 | return ret; |
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339 | } |
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340 | |
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341 | template <typename Number_Type> |
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342 | Polynomial<Number_Type> |
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343 | Polynomial<Number_Type>::operator % (const Polynomial & p) |
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344 | { |
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345 | if (p.is_null()) |
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346 | throw std::logic_error("Polynomial denominator = 0"); |
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347 | |
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348 | if (p.deg == degree_t(0)) |
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349 | return Polynomial(); |
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350 | |
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351 | Polynomial ret = *this; |
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352 | |
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353 | degree_t last = p.deg; |
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354 | |
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355 | while (last > degree_t(0) and p.get_coefficient(last) == number_t(0)) |
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356 | --last; |
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357 | |
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358 | number_t inv = number_t(1) / p.get_coefficient(last); |
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359 | |
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360 | for (degree_t i = ret.deg; i >= p.deg; --i) |
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361 | { |
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362 | number_t q = ret.get_coefficient(i) * inv; |
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363 | |
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364 | for (degree_t j = degree_t(0); j <= p.deg; ++j) |
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365 | ret.set_coefficient(i - j, ret.get_coefficient(i - j) - |
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366 | p.get_coefficient(p.deg - j) * q); |
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367 | } |
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368 | |
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369 | while (ret.deg > degree_t(0) and ret.get_coefficient(ret.deg) == number_t(0)) |
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370 | --ret.deg; |
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371 | |
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372 | return ret; |
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373 | } |
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374 | |
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375 | template <typename Number_Type> |
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376 | Polynomial<Number_Type> & |
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377 | Polynomial<Number_Type>::operator = (const Polynomial & p) |
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378 | { |
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379 | if (&p == this) |
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380 | return *this; |
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381 | |
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382 | deg = p.deg; |
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383 | pol = p.pol; |
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384 | |
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385 | return *this; |
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386 | } |
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387 | |
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388 | template <typename Number_Type> |
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389 | Polynomial<Number_Type> & |
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390 | Polynomial<Number_Type>::operator = (Polynomial && p) |
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391 | { |
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392 | std::swap(deg, p.deg); |
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393 | std::swap(pol, p.pol); |
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394 | |
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395 | return *this; |
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396 | } |
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397 | |
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398 | template <typename Number_Type> |
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399 | bool Polynomial<Number_Type>::operator == (const Polynomial & p) const |
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400 | { |
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401 | if (deg != p.deg) |
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402 | return false; |
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403 | |
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404 | for (degree_t i = degree_t(0); i <= deg; ++i) |
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405 | if (pol.at(i) != p.pol.at(i)) |
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406 | return false; |
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407 | |
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408 | return true; |
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409 | } |
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410 | |
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411 | template <typename Number_Type> |
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412 | bool Polynomial<Number_Type>::operator != (const Polynomial & p) const |
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413 | { |
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414 | return not (*this == p); |
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415 | } |
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416 | |
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417 | template <typename Number_Type> |
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418 | std::string Polynomial<Number_Type>::to_string(const char & var) |
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419 | { |
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420 | std::stringstream sstr; |
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421 | |
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422 | if (deg > degree_t(1)) |
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423 | for (degree_t i = degree_t(0); i < deg - degree_t(1); ++i) |
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424 | sstr << pol.at(i) << var << '^' << deg - i << " + "; |
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425 | |
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426 | if (deg > degree_t(0)) |
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427 | sstr << pol.at(deg - degree_t(1)) << var << " + "; |
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428 | |
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429 | sstr << pol.at(deg); |
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430 | |
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431 | return sstr.str(); |
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432 | } |
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433 | |
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434 | # endif // POLYNOMIAL_H |
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435 | |
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