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OI-codes/Luogu/problem/P2850/P2850.cpp
2021-09-07 21:41:31 +08:00

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;
}