行列式的定义计算

#include "stdafx.h"#include "iostream"#include <stdio.h>#include <string.h>#include <malloc.h>using namespace std;void prt(double *p, int n){int i;for(i = 0; i < n*n; ++i){if(i%n == 0) printf("/n");cout << p[i] << "/t";}cout << "/n";}void f1(double *s, double *p,int n, int i){double *q;int a;//cout << "n = " << n << "/t"<< "i = " << i << endl;for(q = p+n, a = 0; q < p+n*n; ){if(((int)(q-p)-i) % n != 0){*s = *q;s++;a++;}q++;}}int f2(int i){if(i%2 == 0) return 1;else return -1;}double f(double *p, int n){if(n == 1) return (p[0]);if(n == 2) return (p[0]*p[3]-p[1]*p[2]);{int i;double ans = 0;for(i = 0; i < n; ++i){double *s =(double *)malloc(sizeof(double)*(n-1)*(n-1));f1(s,p,n,i);//prt(s,n-1);ans += p[i]*f2(i)*f(s,n-1);free(s);}return ans;}}int main(){double p[3][3]= {{1,0,0},{0,2,0},{0,0,4}};;prt((double*)p,3);cout << endl << f((double*)p,3) << endl;return 0;}