結果
問題 | No.1301 Strange Graph Shortest Path |
ユーザー | nok0 |
提出日時 | 2020-10-30 22:55:27 |
言語 | C++17 (gcc 12.3.0 + boost 1.83.0) |
結果 |
AC
|
実行時間 | 438 ms / 3,000 ms |
コード長 | 4,617 bytes |
コンパイル時間 | 2,591 ms |
コンパイル使用メモリ | 223,668 KB |
実行使用メモリ | 72,724 KB |
最終ジャッジ日時 | 2024-09-13 00:29:11 |
合計ジャッジ時間 | 14,117 ms |
ジャッジサーバーID (参考情報) |
judge5 / judge2 |
(要ログイン)
テストケース
テストケース表示入力 | 結果 | 実行時間 実行使用メモリ |
---|---|---|
testcase_00 | AC | 2 ms
6,816 KB |
testcase_01 | AC | 2 ms
6,812 KB |
testcase_02 | AC | 284 ms
64,868 KB |
testcase_03 | AC | 237 ms
57,268 KB |
testcase_04 | AC | 366 ms
68,044 KB |
testcase_05 | AC | 282 ms
68,096 KB |
testcase_06 | AC | 342 ms
62,776 KB |
testcase_07 | AC | 323 ms
63,828 KB |
testcase_08 | AC | 269 ms
57,684 KB |
testcase_09 | AC | 251 ms
57,816 KB |
testcase_10 | AC | 235 ms
57,864 KB |
testcase_11 | AC | 308 ms
63,892 KB |
testcase_12 | AC | 301 ms
64,552 KB |
testcase_13 | AC | 256 ms
65,764 KB |
testcase_14 | AC | 370 ms
57,972 KB |
testcase_15 | AC | 256 ms
59,656 KB |
testcase_16 | AC | 360 ms
67,660 KB |
testcase_17 | AC | 324 ms
67,260 KB |
testcase_18 | AC | 317 ms
60,728 KB |
testcase_19 | AC | 271 ms
62,124 KB |
testcase_20 | AC | 335 ms
61,692 KB |
testcase_21 | AC | 324 ms
65,564 KB |
testcase_22 | AC | 371 ms
62,280 KB |
testcase_23 | AC | 256 ms
65,728 KB |
testcase_24 | AC | 362 ms
61,576 KB |
testcase_25 | AC | 343 ms
66,588 KB |
testcase_26 | AC | 315 ms
63,864 KB |
testcase_27 | AC | 258 ms
63,588 KB |
testcase_28 | AC | 235 ms
63,240 KB |
testcase_29 | AC | 438 ms
66,644 KB |
testcase_30 | AC | 276 ms
65,988 KB |
testcase_31 | AC | 311 ms
65,780 KB |
testcase_32 | AC | 2 ms
6,940 KB |
testcase_33 | AC | 180 ms
66,960 KB |
testcase_34 | AC | 309 ms
72,724 KB |
ソースコード
#include <bits/stdc++.h> using namespace std; namespace atcoder { template <class Cap, class Cost> struct mcf_graph { public: mcf_graph() {} mcf_graph(int n) : _n(n), g(n) {} int add_edge(int from, int to, Cap cap, Cost cost) { assert(0 <= from && from < _n); assert(0 <= to && to < _n); assert(0 <= cap); assert(0 <= cost); int m = int(pos.size()); pos.push_back({from, int(g[from].size())}); int from_id = int(g[from].size()); int to_id = int(g[to].size()); if(from == to) to_id++; g[from].push_back(_edge{to, to_id, cap, cost}); g[to].push_back(_edge{from, from_id, 0, -cost}); return m; } struct edge { int from, to; Cap cap, flow; Cost cost; }; edge get_edge(int i) { int m = int(pos.size()); assert(0 <= i && i < m); auto _e = g[pos[i].first][pos[i].second]; auto _re = g[_e.to][_e.rev]; return edge{ pos[i].first, _e.to, _e.cap + _re.cap, _re.cap, _e.cost, }; } std::vector<edge> edges() { int m = int(pos.size()); std::vector<edge> result(m); for(int i = 0; i < m; i++) { result[i] = get_edge(i); } return result; } std::pair<Cap, Cost> flow(int s, int t) { return flow(s, t, std::numeric_limits<Cap>::max()); } std::pair<Cap, Cost> flow(int s, int t, Cap flow_limit) { return slope(s, t, flow_limit).back(); } std::vector<std::pair<Cap, Cost>> slope(int s, int t) { return slope(s, t, std::numeric_limits<Cap>::max()); } std::vector<std::pair<Cap, Cost>> slope(int s, int t, Cap flow_limit) { assert(0 <= s && s < _n); assert(0 <= t && t < _n); assert(s != t); // variants (C = maxcost): // -(n-1)C <= dual[s] <= dual[i] <= dual[t] = 0 // reduced cost (= e.cost + dual[e.from] - dual[e.to]) >= 0 for all edge std::vector<Cost> dual(_n, 0), dist(_n); std::vector<int> pv(_n), pe(_n); std::vector<bool> vis(_n); auto dual_ref = [&]() { std::fill(dist.begin(), dist.end(), std::numeric_limits<Cost>::max()); std::fill(pv.begin(), pv.end(), -1); std::fill(pe.begin(), pe.end(), -1); std::fill(vis.begin(), vis.end(), false); struct Q { Cost key; int to; bool operator<(Q r) const { return key > r.key; } }; std::priority_queue<Q> que; dist[s] = 0; que.push(Q{0, s}); while(!que.empty()) { int v = que.top().to; que.pop(); if(vis[v]) continue; vis[v] = true; if(v == t) break; // dist[v] = shortest(s, v) + dual[s] - dual[v] // dist[v] >= 0 (all reduced cost are positive) // dist[v] <= (n-1)C for(int i = 0; i < int(g[v].size()); i++) { auto e = g[v][i]; if(vis[e.to] || !e.cap) continue; // |-dual[e.to] + dual[v]| <= (n-1)C // cost <= C - -(n-1)C + 0 = nC Cost cost = e.cost - dual[e.to] + dual[v]; if(dist[e.to] - dist[v] > cost) { dist[e.to] = dist[v] + cost; pv[e.to] = v; pe[e.to] = i; que.push(Q{dist[e.to], e.to}); } } } if(!vis[t]) { return false; } for(int v = 0; v < _n; v++) { if(!vis[v]) continue; // dual[v] = dual[v] - dist[t] + dist[v] // = dual[v] - (shortest(s, t) + dual[s] - dual[t]) + // (shortest(s, v) + dual[s] - dual[v]) = - shortest(s, t) + // dual[t] + shortest(s, v) = shortest(s, v) - shortest(s, t) >= // 0 - (n-1)C dual[v] -= dist[t] - dist[v]; } return true; }; Cap flow = 0; Cost cost = 0, prev_cost_per_flow = -1; std::vector<std::pair<Cap, Cost>> result; result.push_back({flow, cost}); while(flow < flow_limit) { if(!dual_ref()) break; Cap c = flow_limit - flow; for(int v = t; v != s; v = pv[v]) { c = std::min(c, g[pv[v]][pe[v]].cap); } for(int v = t; v != s; v = pv[v]) { auto& e = g[pv[v]][pe[v]]; e.cap -= c; g[v][e.rev].cap += c; } Cost d = -dual[s]; flow += c; cost += c * d; if(prev_cost_per_flow == d) { result.pop_back(); } result.push_back({flow, cost}); prev_cost_per_flow = d; } return result; } private: int _n; struct _edge { int to, rev; Cap cap; Cost cost; }; std::vector<std::pair<int, int>> pos; std::vector<std::vector<_edge>> g; }; } // namespace atcoder int n, m, u, v, w, c, d; int main() { scanf("%d%d", &n, &m); atcoder::mcf_graph<int, long long> mcf(n + 2 * m); w = n; auto add = [&](int u, int v) { mcf.add_edge(u, w, 2, c); mcf.add_edge(w, v, 1, 0); mcf.add_edge(w, v, 1, d - c); ++w; }; while(m--) { scanf("%d%d%d%d", &u, &v, &c, &d); u--, v--; add(u, v); add(v, u); } auto p = mcf.flow(0, n - 1, 2); assert(p.first == 2); printf("%lld\n", p.second); return 0; }