mirror of
https://git.sb/baoshuo/OI-codes.git
synced 2024-11-09 01:18:47 +00:00
38 lines
835 B
C++
38 lines
835 B
C++
#include <bits/stdc++.h>
|
|
|
|
using namespace std;
|
|
|
|
int t, n, m, w, u, v, p, g[505][505];
|
|
|
|
bool check() {
|
|
for (int k = 1; k <= n; k++) {
|
|
for (int i = 1; i <= n; i++) {
|
|
for (int j = 1; j <= n; j++) {
|
|
g[i][j] = min(g[i][j], g[i][k] + g[k][j]);
|
|
}
|
|
if (g[i][i] < 0) {
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
int main() {
|
|
cin >> t;
|
|
while (t--) {
|
|
memset(g, 0x3f, sizeof(g));
|
|
cin >> n >> m >> w;
|
|
for (int i = 1; i <= m; i++) {
|
|
cin >> u >> v >> p;
|
|
g[u][v] = g[v][u] = min(g[u][v], p);
|
|
}
|
|
for (int i = 1; i <= w; i++) {
|
|
cin >> u >> v >> p;
|
|
g[u][v] = min(g[u][v], -p);
|
|
}
|
|
cout << (check() ? "YES" : "NO") << endl;
|
|
}
|
|
return 0;
|
|
}
|