高斯消元 double类型模板

#include <bits/stdc++.h>
#define ios ios::sync_with_stdio(false)
#define ll long long
#define mp make_pair
#define ull unsigned long long
using namespace std;
const int inf = 0x3f3f3f3f;
const ll INF = 0x3f3f3f3f3f3f3f3f;
const int mod = 1e9 + 7;
const int N = 105;
double ma[N][N];//增广矩阵
double x[N];

int Gauss(int n)
{
    int max_r;//当前这列绝对值最大的行
    int col = 1;//当前处理的列
    double temp;
    for(int i = 1; i <= n; i++){
        max_r = i;
        for(int j = i+1; j <= n; j++){
            if(fabs(ma[i][j]) > fabs(ma[max_r][j])) max_r = j;
        }
        for(int j = 1; j <= n+1; j++) swap(ma[i][j],ma[max_r][j]);
        if(!ma[i][i]) return -1;
        for(int j = 1; j <= n; j++){
            if(j != i){
                double t = ma[j][i]/ma[i][i];
                for(int k = i+1; k <= n+1; k++){
                    ma[j][k] -= ma[i][k]*t;
                }
            }
        }
    }
    for(int i = 1; i <= n; i++){
        x[i] = ma[i][n+1]/ma[i][i];
    }
    return 0;
}
int main(){
    int n; cin >> n;
    for(int i = 1;i <= n;i++){
        for(int j = 1;j <= n+1;j++){
            cin >> ma[i][j];
        }
    }
    int op = Gauss(n);
    if(op == -1) printf("No Solution\n");
    else{
        for(int i = 1; i <= n; i++)
            printf("%.2lf\n",x[i]);
    }
    return 0;
}