1865 웜홀
코드
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#include <bits/stdc++.h>
using namespace std;
int tc, N, M, W, road[501][501];
long long d[501];
bool check[501][501];
vector<int> connect[501];
bool belmanford();
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin >> tc;
while (tc--) {
cin >> N >> M >> W;
int a, b, c;
for (int i = 1; i <= N; i++) {
d[i] = 2000000000000;
connect[i].clear();
}
d[1] = 0;
memset(check, 0, sizeof(check));
for (int i = 0; i < M; i++) {
cin >> a >> b >> c;
connect[a].push_back(b);
connect[b].push_back(a);
if (check[a][b])
road[a][b] = min(road[a][b], c);
else
road[a][b] = c;
road[b][a] = road[a][b];
check[a][b] = true;
check[b][a] = true;
}
for (int i = 0; i < W; i++) {
cin >> a >> b >> c;
connect[a].push_back(b);
road[a][b] = min(road[a][b], -c);
}
if (belmanford())
cout << "YES\n";
else
cout << "NO\n";
}
}
bool belmanford() {
for (int i = 0; i < N - 1; i++) {
for (int j = 1; j <= N; j++) {
for (int k = 0; k < connect[j].size(); k++)
d[connect[j][k]] = min(d[connect[j][k]], d[j] + road[j][connect[j][k]]);
}
}
for (int j = 1; j <= N; j++) {
for (int k = 0; k < connect[j].size(); k++)
if (d[connect[j][k]] > d[j] + road[j][connect[j][k]])
return true;
}
return false;
}