87 lines
1.8 KiB
C++
87 lines
1.8 KiB
C++
#include <algorithm>
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#include <iostream>
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using namespace std;
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const int MAXN1 = 50000;
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const int MAXN2 = 50000;
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const int MAXM = 150000;
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int n1, n2, edges, last[MAXN1], prev[MAXM], head[MAXM];
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int matching[MAXN2], dist[MAXN1], Q[MAXN1];
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bool used[MAXN1], vis[MAXN1];
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void init(int _n1, int _n2) {
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n1 = _n1;
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n2 = _n2;
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edges = 0;
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fill(last, last + n1, -1);
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}
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void addEdge(int u, int v) {
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head[edges] = v;
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prev[edges] = last[u];
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last[u] = edges++;
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}
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void bfs() {
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fill(dist, dist + n1, -1);
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int sizeQ = 0;
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for (int u = 0; u < n1; ++u) {
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if (!used[u]) {
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Q[sizeQ++] = u;
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dist[u] = 0;
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}
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}
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for (int i = 0; i < sizeQ; i++) {
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int u1 = Q[i];
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for (int e = last[u1]; e >= 0; e = prev[e]) {
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int u2 = matching[head[e]];
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if (u2 >= 0 && dist[u2] < 0) {
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dist[u2] = dist[u1] + 1;
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Q[sizeQ++] = u2;
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}
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}
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}
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}
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bool dfs(int u1) {
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vis[u1] = true;
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for (int e = last[u1]; e >= 0; e = prev[e]) {
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int v = head[e];
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int u2 = matching[v];
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if (u2 < 0 || !vis[u2] && dist[u2] == dist[u1] + 1 && dfs(u2)) {
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matching[v] = u1;
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used[u1] = true;
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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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int maxMatching() {
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fill(used, used + n1, false);
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fill(matching, matching + n2, -1);
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for (int res = 0;;) {
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bfs();
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fill(vis, vis + n1, false);
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int f = 0;
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for (int u = 0; u < n1; ++u)
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if (!used[u] && dfs(u))
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++f;
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if (!f)
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return res;
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res += f;
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}
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}
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int main() {
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init(2, 2);
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addEdge(0, 0);
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addEdge(0, 1);
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addEdge(1, 1);
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cout << (2 == maxMatching()) << endl;
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}
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