加列法计算lower unit matrix inversion

#include
 
#define NA 4
 
int main()
{
        //下三角矩阵 lower
        float    lower[NA][NA]={
                                1,0,0,0,
                                4,1,0,0,
                                5,3,1,0,
                                6,7,6,1
                                        };
        int dia=NA;
        int i, j, n;
        //针对矩阵第一列计算逆
        for(i = 1; i < dia; i++ )
        {
                lower[i][0]=-lower[i][0];
        }
        //dia is order of lower matrix
        // 保存在原矩阵的数组中
        for(n=1;n-1;n++)
        {
                for(i = n+1; i < dia; i++)
                {
                        for(j = 0; j < n; j++)
                        {
                                lower[i][j]-=lower[n][j]*lower[i][n];
                        }
                        lower[i][n]=-lower[i][n];
                }
        }
 
        for(i=0;i
        {
                for(j=0;j
                {
                        printf("%5.2f ",lower[i][j]);
                }
                printf("\n");
        }
 
        return 0;
 
}

gcc hello...c