# | 제출 시각 | 아이디 | 문제 | 언어 | 결과 | 실행 시간 | 메모리 |
---|---|---|---|---|---|---|---|
1197413 | adiyer | Swapping Cities (APIO20_swap) | C++20 | 0 ms | 0 KiB |
#include <bits/stdc++.h>
using namespace std;
const int MAXN = 2e5 + 11;
int n, m, mn, mx, ok;
bool was[MAXN];
vector < int > cmp;
vector < int > g[MAXN];
vector < pair < int, pair < int, int > > > reb;
void init(int N, int M, vector < int > U, vector < int > V, vector < int > W){
n = N, m = M;
for(int i = 0; i < m; i++) reb.push_back({W[i], {U[i], V[i]}});
sort(reb.begin(), reb.end());
}
void dfs(int v){
was[v] = 1, cmp.push_back(v);
for(int u : g[v])
if(!was[u])
dfs(u);
}
bool f(int x, int y, int till){
for(int i = 0; i <= till; i++) g[reb[i].second.first].push_back(reb[i].second.second), g[reb[i].second.second].push_back(reb[i].second.first);
cmp.clear(), dfs(x), mn = n, mx = 0, ok = was[y];
for(int v : cmp) mn = min(mn, (int) g[v].size()), mx = max(mx, (int) g[v].size()), was[v] = 0;
for(int i = 0; i <= till; i++) g[reb[i].second.first].clear(), g[reb[i].second.second].clear();
return ((mx > 2 || mn >= 2) && (ok));
}
int getMinimumFuelCapacity(int X, int Y) {
int l = 0, r = m;
while(r - l > 1){
int md = (l + r) / 2;
if(f(X, Y, md)) r = md;
else l = md;
}
if(r == m) return -1;
return reb[r].first;
}
int main() {
int N, M;
assert(2 == scanf("%d %d", &N, &M));
std::vector<int> U(M), V(M), W(M);
for (int i = 0; i < M; ++i) {
assert(3 == scanf("%d %d %d", &U[i], &V[i], &W[i]));
}
int Q;
assert(1 == scanf("%d", &Q));
std::vector<int> X(Q), Y(Q);
for (int i = 0; i < Q; ++i) {
assert(2 == scanf("%d %d", &X[i], &Y[i]));
}
init(N, M, U, V, W);
std::vector<int> minimum_fuel_capacities(Q);
for (int i = 0; i < Q; ++i) {
minimum_fuel_capacities[i] = getMinimumFuelCapacity(X[i], Y[i]);
}
for (int i = 0; i < Q; ++i) {
printf("%d\n", minimum_fuel_capacities[i]);
}
return 0;
}