题目链接 错误代码：

#include<bits/stdc++.h>
using namespace std;
const int N = 1010;
const double OP = 1e-6;
int n;
double a[N][N];
int gauss()
{
    int c = 0, r = 0;
    for(c = 0, r = 0; c < n; c++)
    {
        int t = r;
        for(int i = r; i < n; i ++)
            if(fabs(a[i][c]) > fabs(a[t][c]))
                t = i;
        if(fabs(a[t][c]) < OP) continue;
        for(int i = c; i < n + 1; i ++) swap(a[t][i], a[r][i]);
        for(int i = n; i >= c; i --) a[r][i] /= a[r][c];
        for(int i = r + 1; i < n; i ++)
            if(fabs(a[i][c]) > OP)
                for(int j = n; j >= c; j --)
                    a[i][j] -= a[r][j] * a[i][c];
        r ++;
    }
    if(r < n)
    {
        return 1;
    }
    for(int i = n - 1; i >= 0; i --)
        for(int j = i + 1; j < n; j ++)
            a[i][n] -= a[j][n] * a[i][j];
    return 0;
}
int main()
{
    cin >> n;
    for (int i = 0; i < n; i ++ )
        for (int j = 0; j < n + 1; j ++ )
            cin >> a[i][j];
    int g = gauss();
    if (g == 0)
    {
        for (int i = 0; i < n; i ++ )printf("%.2lf\n", a[i][n]);
    }
    else puts("No solution");
    return 0;
}

WA了一个点