#include <stdio.h>
#include <string.h>
typedef int number;
number determinant(number **m, int n) {
return 6;
}
void swap_cell(number **m, int x1, int y1, int x2, int y2) {
//printf("(%d %d)<->(%d %d)\n", x1, y1, x2, y2);
number l = m[x1][y1];
m[x1][y1] = m[x2][y2];
m[x2][y2] = l;
}
void swap_x(number **m, int n, int fromy, int toy) {
int i;
for (i = 0; i < n; ++i) swap_cell(m, i, fromy, i, toy);
}
void swap_y(number **m, int n, int fromx, int tox) {
int i;
for (i = 0; i < n; ++i) swap_cell(m, fromx, i, tox, i);
}
number _minor(number **m, int n, int i, int j) {
swap_x(m, n, j, n-1);
swap_y(m, n, i, n-1);
number r = (i*j) & 1 ? -1 :+1;
r*=determinant(m, n - 1);
swap_y(m, n, i, n-1);
swap_x(m, n, j, n-1);
return r;
}
int main(){
number row0[3] = {1,4,7};
number row1[3] = {2,5,8};
number row2[3] = {3,6,9};
number* a[3] = {row0, row1, row2};
printf("%d\n", _minor(a, 3, 0, 1));
return 0;
}
|
