結果
問題 | No.1301 Strange Graph Shortest Path |
ユーザー |
|
提出日時 | 2020-11-27 22:50:13 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 344 ms / 3,000 ms |
コード長 | 4,136 bytes |
コンパイル時間 | 1,992 ms |
コンパイル使用メモリ | 141,320 KB |
最終ジャッジ日時 | 2025-01-16 08:10:50 |
ジャッジサーバーID (参考情報) |
judge5 / judge3 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 2 |
other | AC * 33 |
ソースコード
#include <iostream>#include <vector>#include <algorithm>#include <cmath>#include <queue>#include <string>#include <map>#include <set>#include <stack>#include <tuple>#include <deque>#include <array>#include <numeric>#include <bitset>#include <iomanip>#include <cassert>#include <chrono>#include <random>#include <limits>#include <iterator>#include <functional>#include <sstream>#include <fstream>#include <complex>#include <cstring>#include <unordered_map>using namespace std;using ll = long long;using P = pair<int, int>;constexpr int INF = 1001001001;// constexpr int mod = 1000000007;constexpr int mod = 998244353;template<class T>inline bool chmax(T& x, T y){if(x < y){x = y;return true;}return false;}template<class T>inline bool chmin(T& x, T y){if(x > y){x = y;return true;}return false;}template<typename flow_t, typename cost_t>struct PrimalDual{const cost_t INF;struct edge{int to;flow_t cap;cost_t cost;int rev;bool isrev;edge(int to, flow_t cap, cost_t cost, int rev, bool isrev): to(to), cap(cap), cost(cost), rev(rev), isrev(isrev) {}};vector<vector<edge>> graph;vector<cost_t> potential; // ポテンシャルテーブルvector<cost_t> min_cost; // 最小コストテーブルvector<int> prevv, preve; // 経路復元用PrimalDual(int V, cost_t INF = numeric_limits<cost_t>::max() / 2) : graph(V), INF(INF) {}void add_edge(int from, int to, flow_t cap, cost_t cost){graph[from].emplace_back(edge(to, cap, cost, graph[to].size(), false));graph[to].emplace_back(edge(from, 0, -cost, graph[from].size() - 1, true));}cost_t min_cost_flow(int s, int t, flow_t f){int V = (int)graph.size();cost_t ret = 0;using Pi = pair<cost_t, int>;priority_queue<Pi, vector<Pi>, greater<Pi>> que;potential.assign(V, 0);preve.assign(V, -1);prevv.assign(V, -1);while(f > 0){min_cost.assign(V, INF); // 残余グラフ上の最小コストを毎回調べるque.emplace(0, s);min_cost[s] = 0;while(!que.empty()){Pi p = que.top();que.pop();if(min_cost[p.second] < p.first) continue;for(int i = 0; i < (int)graph[p.second].size(); ++i){edge &e = graph[p.second][i];// ポテンシャルを用いたコスト比較cost_t nextCost = min_cost[p.second] + e.cost + potential[p.second] - potential[e.to];if(e.cap > 0 && min_cost[e.to] > nextCost){min_cost[e.to] = nextCost;prevv[e.to] = p.second, preve[e.to] = i;que.emplace(min_cost[e.to], e.to);}}}if(min_cost[t] == INF) return -1;for(int v = 0; v < V; ++v) potential[v] += min_cost[v]; // ポテンシャルの更新flow_t addflow = f;// s-t間最短路の沿って目一杯流すfor(int v = t; v != s; v = prevv[v]){addflow = min(addflow, graph[prevv[v]][preve[v]].cap);}f -= addflow;ret += addflow * potential[t];for(int v = t; v != s; v = prevv[v]){edge &e = graph[prevv[v]][preve[v]];e.cap -= addflow;graph[v][e.rev].cap += addflow;}}return ret;}};int main(){ios::sync_with_stdio(false);cin.tie(nullptr);int N, M;cin >> N >> M;PrimalDual<int, ll> pd(N);int s = 0, t = N - 1;for(int i = 0; i < M; ++i){int u, v, c, d;cin >> u >> v >> c >> d;--u, --v;pd.add_edge(u, v, 1, c);pd.add_edge(v, u, 1, c);pd.add_edge(u, v, 1, d);pd.add_edge(v, u, 1, d);}cout << pd.min_cost_flow(s, t, 2) << endl;}