59 lines
1.4 KiB
C++
59 lines
1.4 KiB
C++
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// uoj-78.cc
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#include<bits/stdc++.h>
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using namespace std;
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int main() {
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ios_base::sync_with_stdio(0), cin.tie(NULL);
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int nl, nr, m;
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cin >> nl >> nr >> m;
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vector<vector<int>> left(nl+1);
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vector<vector<int>> right(nr+1);
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vector<int> choice_left(nl+1);
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vector<int> choice_right(nr+1);
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vector<int> vis(nl+1);
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while(m--) {
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int v, u;
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cin >> v >> u;
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left[v].push_back(u);
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right[u].push_back(v);
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}
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function<bool(int)> dfs = [&](int v) -> bool {
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if (vis[v]) return false;
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vis[v] = true;
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for (auto&& u : left[v]) {
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if (choice_right[u]) {
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int t = choice_right[u];
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if (dfs(t)) {
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choice_left[v] = u;
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choice_right[u] = v;
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vis[v] = false;
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return true;
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}
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} else {
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choice_left[v] = u;
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choice_right[u] = v;
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vis[v] = false;
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return true;
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}
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}
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return false;
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};
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for (int i = 1; i <= nl; ++i) {
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if (!choice_left[i]) {
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dfs(i);
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}
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}
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vector<int> res;
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int cnt = 0;
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for (int i = 1; i <= nl; ++i) {
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if (choice_left[i]) {
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++cnt;
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}
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res.push_back(choice_left[i]);
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}
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cout << cnt << endl;
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for (auto&& j : res)
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cout << j << ' ';
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}
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