最短路之Floyd（多源）HDU 1874

Posted 2020-12-28 xiao-xue-di

#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;
#define INF 10000
const int maxn = 300;
int r[maxn][maxn];
int main() {
    int n, m;
    while (cin>>n>>m)
     {
        memset (r, INF, sizeof(r));
        int x, y, v;
for (int i = 0; i < m; i++)
         {
            cin>>x>>y>>v;
            if (r[x][uy] > v)
                r[x][y] = r[y][x] = v;
        }
for (int i = 0; i < n ;i++)
            r[i][i] = 0;
for (int k = 0; k < n; k++)
            for (int i = 0; i < n; i++)
                for (int j = 0; j < n; j++)
                {
                    if (r[i][k] + r[k][j] < r[i][j])
                           r[i][j] = r[j][i] = r[i][k] + r[k][j];
                }
cin>>x>>y;
if (r[x][y] < INF)
            cout<<r[x][y]<<endl;
        else
            cout<<"-1"<<endl;
    }
    return 0;
}