VC++ (main.cpp)：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 | #include "stdafx.h"#include <iostream>#include <fstream>#include <string>#include <regex>#include <iomanip>using namespace std;void print(double *Arr, int m){ int i = 0, j = 0; for(i=0;i<m;i++) { for(j=0;j<m;j++) { cout << *(Arr+i*m+j) << setprecision(2) << "\t"; } cout << endl; }}void printInverse(double *Matrix, double *Inverse, int m){ int i = 0, j = 0; for(i=0;i<m;i++) { for(j=0;j<m;j++) { cout << *(Matrix+i*m+j) << setprecision(2) << "\t"; } cout << "|\t"; for(j=0;j<m;j++) { cout << *(Inverse+i*m+j) << setprecision(2) << "\t"; } cout << endl; }}void readfile(string filePath, double *Matrix){ int m = 0, n = 0, i = 0; string lines = ""; string::const_iterator start; match_results<string::const_iterator> matchMatrix; //迭代器 regex regMatrix("([0-9]+)+"); ifstream outputFile(filePath); if (outputFile.is_open()) //Check File { while(outputFile.good()) { getline(outputFile, lines); start = lines.begin(); while (regex_search(start, lines.cend(), matchMatrix, regMatrix)) { *(Matrix+i) = atof(matchMatrix[1].str().c_str()); i++; start = matchMatrix[0].second; } m++; } outputFile.close(); }}double plusnum(double num){ if(num < 0) return -1 * num; return num;}void rowSwap(double *Matrix, int ma, int mb, int m){ int i = 0; double *Temp = new double[m]; for(i=0;i<m;i++) { *(Temp+i) = *(Matrix+ma*m+i); *(Matrix+ma*m+i) = *(Matrix+mb*m+i); *(Matrix+mb*m+i) = *(Temp+i); }}void inverse(double *Matrix, double *Inverse, int m){ int i = 0, j = 0, k = 0; double temp = 0; //*(Matrix + rows * m + columns) 看成 Matrix[rows][columns] for(int i=0; i<m; i++) { for(int j=i+1; j<m; j++) { if(plusnum(*(Matrix + j * m + i)) > plusnum(*(Matrix + i * m + i))) { rowSwap(Matrix, i, j, m); // 互換Matrix矩陣兩行 rowSwap(Inverse, i, j, m); // 互換Inverse矩陣兩行 //cout << "[" << i << "][" << j << "]Swap:" << endl; //printInverse(Matrix, Inverse, m); } } // 消去 for(int j=0; j<m; j++) //第 i 次消去運算，以第 i 行作為主要行，將其上下各行的第 i 列元素化為零 { if(j != i) { // 進行消去運算，將第 i 列上下方的元素化為零 double temp = *(Matrix + j * m + i) / *(Matrix + i * m + i); // 注意此處 k 可從 i+1 開始 //for(int k=i+1; k<m; k++) for(int k=0; k<m; k++) { *(Matrix + j * m + k) -= (*(Matrix + i * m + k) * temp); } // 注意此處 k 要從 0 開始 for(int k=0; k<m; k++) { *(Inverse + j * m + k) -= (*(Inverse + i * m + k) * temp); } //cout << "[" << i << "][" << j << "]Matrix:" << endl; //printInverse(Matrix, Inverse, m); } } } // Matrix 已經是對角矩陣，只要在將其對角線元素化為 1 即可 // 此時僅需對 Inverse 矩陣作運算 //cout << "[" << i << "][" << j << "]Inverse:" << endl; //printInverse(Matrix, Inverse, m); for(int i=0; i<m; i++) { for(int j=0; j<m; j++) { *(Inverse + i * m + j) /= *(Matrix + i * m + i); } //cout << "[" << i << "][" << j << "]Inverse:" << endl; //printInverse(Matrix, Inverse, m); }} int main(int argc, char *argv[]){ const int m = 4; int i = 0, j = 0; double Matrix[m][m] = {}; double Inverse[m][m] = {}; for(i=0;i<m;i++) { for(j=0;j<m;j++) { if(i == j) Inverse[i][j] = 1; else Inverse[i][j] = 0; } } readfile("matrix.txt", &Matrix[0][0]); cout << "Matrix:" << endl; print(&Matrix[0][0], m); inverse(&Matrix[0][0], &Inverse[0][0], m); cout << endl; cout << "Inverse:" << endl; print(&Inverse[0][0], m); system("pause"); return 0;} |
說明：
先讀取矩陣數據再利用指標的方式求得n維度反矩陣的解。
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