Created
December 10, 2018 23:17
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Total destruction
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#include <iostream> | |
#include <vector> | |
#include <unordered_set> | |
using namespace std; | |
int get(vector<int>& parent, int v) { | |
if (parent[v] == v) return v; | |
return parent[v] = get(parent, parent[v]); | |
} | |
int main() { | |
int n, m; | |
cin >> n >> m; | |
vector<pair<int, int>> g(m); | |
for (int i = 0; i < m; ++i) { | |
cin >> g[i].first >> g[i].second; | |
--g[i].first; | |
--g[i].second; | |
} | |
vector<int> parent(n); | |
for (int i = 0; i < n; ++i) { | |
parent[i] = i; | |
} | |
vector<unordered_set<int>> queries(n); | |
int q; | |
cin >> q; | |
vector<int> res(q, 0); | |
for (int i = 0; i < q; ++i) { | |
int u, v; | |
cin >> u >> v; | |
--u; | |
--v; | |
queries[u].insert(i); | |
queries[v].insert(i); | |
} | |
for (int i = g.size() - 1; i >= 0; --i) { | |
int u = get(parent, g[i].first); | |
int v = get(parent, g[i].second); | |
if (u == v) { | |
continue; | |
} | |
if (queries[u].size() > queries[v].size()) { | |
swap(u, v); | |
} | |
for (int x : queries[u]) { | |
if (queries[v].count(x)) { | |
res[x] = i + 1; | |
queries[v].erase(x); | |
} else { | |
queries[v].insert(x); | |
} | |
} | |
parent[u] = v; | |
} | |
for (int i = 0; i < res.size(); ++i) { | |
cout << res[i] << endl; | |
} | |
} | |
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