Strassen 알고리즘 구현 (정방행렬, 차원값은 2의 지수값 즉, 2^d)
입력 파일 형식 : 차원\n 행별 값들
예. 2
3 4 2 5
5 4 7 8
[소스코드]
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 | #include <iostream> #include <string> #include <algorithm> #include <fstream> #include <sstream> #include <string.h> #include <stdio.h> using namespace std; #define MAX_SIZE 1000 class matrix { private : int mat1[MAX_SIZE][MAX_SIZE]; int mat2[MAX_SIZE][MAX_SIZE]; int result[MAX_SIZE][MAX_SIZE]; int n; void strassen(int n, int a1[][MAX_SIZE], int b1[][MAX_SIZE], int c1[][MAX_SIZE]); public: void init(); const void print(); void strassen_start(); }; void matrix::strassen_start() { int i, j, k, l; for (i = 0; i < n; i++) { for (j = 0; j < n; j++) { result[i][j] = 0;//초기화 } } strassen(n, mat1, mat2, result); } void matrix::strassen(int n, int a1[][MAX_SIZE], int b1[][MAX_SIZE], int c1[][MAX_SIZE]) { int i, j; int m1[MAX_SIZE][MAX_SIZE], m2[MAX_SIZE][MAX_SIZE], m3[MAX_SIZE][MAX_SIZE], m4[MAX_SIZE][MAX_SIZE], m5[MAX_SIZE][MAX_SIZE], m6[MAX_SIZE][MAX_SIZE], m7[MAX_SIZE][MAX_SIZE]; int temp1[MAX_SIZE][MAX_SIZE], temp2[MAX_SIZE][MAX_SIZE]; int sm1, sm2, sm3, sm4, sm5, sm6, sm7; if (n <= 2) { sm1 = (a1[0][0] + a1[1][1])*(b1[0][0] + b1[1][1]); sm2 = (a1[1][0] + a1[1][1])*b1[0][0]; sm3 = a1[0][0] * (b1[0][1] - b1[1][1]); sm4 = a1[1][1] * (b1[1][0] - b1[0][0]); sm5 = (a1[0][0] + a1[0][1]) * b1[1][1]; sm6 = (a1[1][0] - a1[0][0])*(b1[0][0] +b1[0][1]); sm7 = (a1[0][1] - a1[1][1])*(b1[1][0] + b1[1][1]); c1[0][0] = sm1 + sm4 - sm5 + sm7; c1[0][1] = sm3 + sm5; c1[1][0] = sm2 + sm4; c1[1][1] = sm1 + sm3 - sm2 + sm6; } else { for (i = 0; i < n / 2; i++) for (j = 0; j < n / 2; j++) temp1[i][j] = a1[i][j] + a1[i + n / 2][j + n / 2]; for (i = 0; i < n / 2; i++) for (j = 0; j < n / 2; j++) temp2[i][j] = b1[i][j] + b1[i + n / 2][j + n / 2]; strassen(n / 2, temp1,temp2, m1); //m1 for (i = 0; i < n / 2; i++) for (j = 0; j < n / 2; j++) temp1[i][j] = a1[i + n / 2][j] + a1[i + n / 2][j + n / 2]; for (i = 0; i < n / 2; i++) for (j = 0; j < n / 2; j++) temp2[i][j] = b1[i][j]; strassen(n / 2, temp1, temp2, m2); //m2 for (i = 0; i < n / 2; i++) for (j = 0; j < n / 2; j++) temp1[i][j] = a1[i][j]; for (i = 0; i < n / 2; i++) for (j = 0; j < n / 2; j++) temp2[i][j] = b1[i][j + n / 2] - b1[i + n / 2][j + n / 2]; strassen(n / 2, temp1, temp2, m3); //m3 for (i = 0; i < n / 2; i++) for (j = 0; j < n / 2; j++) temp1[i][j] = a1[i + n / 2][j + n / 2]; for (i = 0; i < n / 2; i++) for (j = 0; j < n / 2; j++) temp2[i][j] = b1[i + n / 2][j] - b1[i][j]; strassen(n / 2, temp1, temp2, m4); //m4 for (i = 0; i < n / 2; i++) for (j = 0; j < n / 2; j++) temp1[i][j] = a1[i][j] + a1[i][j + n / 2]; for (i = 0; i < n / 2; i++) for (j = 0; j < n / 2; j++) temp2[i][j] = b1[i + n / 2][j + n / 2]; strassen(n / 2, temp1, temp2, m5); //m5 for (i = 0; i < n / 2; i++) for (j = 0; j < n / 2; j++) temp1[i][j] = a1[i + n / 2][j] - a1[i][j]; for (i = 0; i < n / 2; i++) for (j = 0; j < n / 2; j++) temp2[i][j] = b1[i][j] + b1[i][j + n / 2]; strassen(n / 2, temp1, temp2, m6); //m6 for (i = 0; i < n / 2; i++) for (j = 0; j < n / 2; j++) temp1[i][j] = a1[i][j + n / 2] - a1[i + n / 2][j + n / 2]; for (i = 0; i < n / 2; i++) for (j = 0; j < n / 2; j++) temp2[i][j] = b1[i + n / 2][j] + b1[i + n / 2][j + n / 2]; strassen(n / 2, temp1, temp2, m7); //m7 for (i = 0; i < n / 2; i++) for (j = 0; j < n / 2; j++) c1[i][j] = m1[i][j] + m4[i][j] - m5[i][j] + m7[i][j]; for (i = 0; i < n / 2; i++) for (j = 0; j < n / 2; j++) c1[i][j + n / 2] = m3[i][j] + m5[i][j]; for (i = 0; i < n / 2; i++) for (j = 0; j < n / 2; j++) c1[i + n / 2][j] = m2[i][j] + m4[i][j]; for (i = 0; i < n / 2; i++) for (j = 0; j < n / 2; j++) c1[i + n / 2][j + n / 2] = m1[i][j] + m3[i][j] - m2[i][j] + m6[i][j]; //이런 식으로 계산하여 각각 스트라센을 호출한다 } //출력 for (i = 0; i < n; i++) { for (j = 0; j < n; j++) { cout<<c1[i][j]; cout << " "; } cout<<endl; } } void matrix::init() { //행렬의 크기 결정 FILE *file; int *data; int i, j; //행렬의 크기를 부여받음 file = fopen("matrix.txt","r"); if (file != NULL) { fscanf(file, "%d", &n); for (i = 0; i < n; i++) { for (j = 0; j < n; j++) { fscanf(file, "%d", &mat1[i][j]); } } for (i = 0; i < n; i++) { for (j = 0; j < n; j++) { fscanf(file, "%d", &mat2[i][j]); } } //행렬 만들기 } } const void matrix::print() { int i, j; cout << "행렬 A"; cout << endl; for (i = 0; i < n; i++) { for (j = 0; j < n; j++) { cout<<" "<< mat1[i][j]; } cout << endl; } cout << endl; cout << "행렬 B"; cout << endl; for (i = 0; i < n; i++) { for (j = 0; j < n; j++) { cout << " " << mat2[i][j]; } cout << endl; } cout << endl; } int main(void) { matrix m; m.init(); m.print(); cout << "결과"; cout << endl; m.strassen_start(); } | cs |