洛谷 B3611 【模板】传递闭包

只要距离不是0x3f3f3 就代表能联通

#include <bits/stdc++.h>
using namespace std;//防X抄袭 
int n;
int a[110][110];
#define inf 0x3f3f3f3f
int main()
{
    cin >> n;
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= n; j++)
            {
            	cin >> a[i][j];
            	if(a[i][j]==0)
					a[i][j]= inf;
			}
    for (int k = 1; k <= n; k++)//课上讲的floyd 
        for (int i = 1; i <= n; i++)
            for (int j = 1; j <= n; j++)
             if(a[i][j]>a[i][k]+a[k][j] )
                    a[i][j]=a[i][k]+a[k][j];
               
    for (int i = 1; i <= n; i++)
    {
        for (int j = 1; j <= n; j++)
        if(a[i][j]==inf)
        	cout<<"0 ";
        else
            cout <<"1 ";
        cout << endl;
    }
    return 0;
}