銆愭ā鏉裤€戦珮鏂秷鍏冩硶

Posted 2020-11-12

鏍囩锛?a href='http://www.mamicode.com/so/1/swap' title='swap'>swap   pre   using   int   clu   娑堝厓   space   妯℃澘   n+1   

棰樼洰鎻忚堪锛?a href="https://www.luogu.org/problem/P3389" class="uri">https://www.luogu.org/problem/P3389

#include<bits/stdc++.h>
using namespace std;
int n;
double a[105][105];
int main(){
    scanf("%d",&n);
    for(int i=1;i<=n;i++)
        for(int j=1;j<=n+1;j++)
            scanf("%lf",&a[i][j]);
    for(int i=1;i<=n;i++){
        int pi=i;
        while(!a[pi][i]&&pi<=n) pi++;
        if(pi>n){
            printf("No Solution
");
            return 0;
        }
        for(int j=1;j<=n+1;j++) 
            swap(a[i][j],a[pi][j]);
        double t=a[i][i];
        for(int j=1;j<=n+1;j++) 
            a[i][j]/=t;
        for(int j=1;j<=n;j++){
            if(j!=i){
                double t=a[j][i];
                for(int m=1;m<=n+1;m++)
                    a[j][m]-=t*a[i][m];
            }
        }
    }
    for(int i=1;i<=n;i++) 
        printf("%.2lf
",a[i][n+1]);
    return 0;
}