42 lines
1.1 KiB
C++
42 lines
1.1 KiB
C++
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struct dinic {
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// ...
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};
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void solve() {
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read(int, n, m, s, t);
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dinic net(n + 1);
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int S = 0, T = n + 1;
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vector<ll> init(n + 1);
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for (int i = 0 ;i < m; ++i) {
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read(ll, u, v, lower, upper);
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init[v] += lower;
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init[u] -= lower;
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net.add_edge(u, v, upper - lower);
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}
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ll sum = 0;
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for (int i =1; i <= n; ++i) {
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if (init[i] > 0) {
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net.add_edge(S, i, init[i]);
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sum += init[i];
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} else if (init[i] < 0) {
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net.add_edge(i, T, -init[i]);
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}
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}
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net.add_edge(t, s, INFLL, 1, 1); // WARN: s->t is wrong
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if (sum != net.run(S, T)) {
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cout << "please go home to sleep\n";
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} else {
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int m = net.edges[t].size();
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int curr;
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for (int i = 0; i < m; ++i) {
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if (net.edges[t][i].mark) {
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net.edges[t][i].cap = 0;
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net.edges[net.edges[t][i].to][net.edges[t][i].rev].cap = 0;
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curr = net.edges[t][i].flow; // WARN: real flow
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break;
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}
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}
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cout << curr - net.run(t, s) << '\n';
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}
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}
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