結果

問題 No.1301 Strange Graph Shortest Path
ユーザー outline
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
このコードへのチャレンジ
(要ログイン)
ファイルパターン 結果
sample AC * 2
other AC * 33
権限があれば一括ダウンロードができます

ソースコード

diff #
プレゼンテーションモードにする

#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; //
vector<cost_t> min_cost; //
vector<int> prevv, preve; //
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); // 調
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];
//
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]; //
flow_t addflow = f;
// s-t沿
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;
}
הההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההה
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
0