Tyvj P2059(传递闭包）

朴素的传递闭包

#include<iostream>#include<cstdio>#include<cstdlib>#include<cmath>#include<cstring>#include<functional>#include<algorithm>#include<cctype>using namespace std;#define MAXN (100+10)#define MAXM (4500+10)bool f[MAXN][MAXN]={0};int n,m;int main(){cin>>n>>m;for (int i=1;i<=m;i++){int x,y;scanf("%d%d",&x,&y);f[x][y]=1;}for (int k=1;k<=n;k++)for (int i=1;i<=n;i++)for (int j=1;j<=n;j++)f[i][j]=f[i][j]||f[i][k]&&f[k][j];int tot=0;for (int i=1;i<=n;i++){for (int j=1;j<=n;j++)if (i!=j&&!(f[i][j]||f[j][i])) {tot--;break;}tot++;}//for (int i=1;i<=n;i++) for (int j=1;j<=n;j++) cout<<f[i][j]<<' ';cout<<tot;return 0;}