求逆矩阵——C语言

Posted 2022-08-22 Rachel-Zhang

#include<stdio.h>
#define N 10
int getA(int arcs[N][N],int n)//按第一行展开计算|A|

	if(n==1)
	
		return arcs[0][0];
	
	int ans = 0;
	int temp[N][N];
	int i,j,k;
	for(i=0;i<n;i++)
	
		for(j=0;j<n-1;j++)
		
			for(k=0;k<n-1;k++)
			
				temp[j][k] = arcs[j+1][(k>=i)?k+1:k];
				
			
		
		int t = getA(temp,n-1);
		if(i%2==0)
		
			ans += arcs[0][i]*t;
		
		else
		
			ans -=  arcs[0][i]*t;
		
	
	return ans;

void getAStart(int arcs[N][N],int n,int ans[N][N])//计算每一行每一列的每个元素所对应的余子式，组成A*

	if(n==1)
	
		ans[0][0] = 1;
		return;
	
	int i,j,k,t;
	int temp[N][N];
	for(i=0;i<n;i++)
	
		for(j=0;j<n;j++)
		
			for(k=0;k<n-1;k++)
			
				for(t=0;t<n-1;t++)
				
					temp[k][t] = arcs[k>=i?k+1:k][t>=j?t+1:t];
				
			

		
			ans[j][i]  =  getA(temp,n-1);
			if((i+j)%2 == 1)
			
				ans[j][i] = - ans[j][i];
			
		
	


int main()

    int arcs[N][N];
	int astar[N][N];
	int i,j;
	int n;
	while(scanf("%d",&n)!=EOF && n)
	
		for(i=0;i<n;i++)
		
			for(j=0;j<n;j++)
			
				scanf("%d",&arcs[i][j]);
			
		
	
		int a = getA(arcs,n);
		if(a==0)
		
			printf("can not transform!\\n");
		
		else
		
			getAStart(arcs,n,astar);
			for(i=0;i<n;i++)
			
				for(j=0;j<n;j++)
				
					printf("%.3lf ",(double)astar[i][j]/a);
				
				printf("\\n");
			
		
		printf("\\n");

	
	

	return 0;