結果

問題 No.1301 Strange Graph Shortest Path
ユーザー tokusakuraitokusakurai
提出日時 2020-11-27 22:32:55
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 218 ms / 3,000 ms
コード長 3,683 bytes
コンパイル時間 2,522 ms
コンパイル使用メモリ 208,340 KB
最終ジャッジ日時 2025-01-16 07:55:07
ジャッジサーバーID
(参考情報)
judge5 / judge2
このコードへのチャレンジ
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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 <bits/stdc++.h>
using namespace std;
#define rep(i, n) for(int i = 0; i < n; i++)
#define rep2(i, x, n) for(int i = x; i <= n; i++)
#define rep3(i, x, n) for(int i = x; i >= n; i--)
#define each(e, v) for(auto &e: v)
#define pb push_back
#define eb emplace_back
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define sz(x) (int)x.size()
using ll = long long;
using pii = pair<int, int>;
using pil = pair<int, ll>;
using pli = pair<ll, int>;
using pll = pair<ll, ll>;
const int MOD = 1000000007;
//const int MOD = 998244353;
const int inf = (1<<30)-1;
const ll INF = (1LL<<60)-1;
template<typename T> bool chmax(T &x, const T &y) {return (x < y)? (x = y, true) : false;};
template<typename T> bool chmin(T &x, const T &y) {return (x > y)? (x = y, true) : false;};
struct io_setup{
io_setup(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout << fixed << setprecision(15);
}
} io_setup;
template<typename T>
struct Min_Cost_Flow{
struct edge{
int to; T cap, cost; int rev;
edge(int to, T cap, T cost, int rev) : to(to), cap(cap), cost(cost), rev(rev) {}
};
vector<vector<edge>> es;
vector<T> d, h;
vector<int> pre_v, pre_e;
const T INF_T;
const int n;
Min_Cost_Flow(int n) : INF_T(numeric_limits<T>::max()), n(n){
es.resize(n), d.resize(n), h.resize(n), pre_v.resize(n), pre_e.resize(n);
}
void add_edge(int from, int to, T cap, T cost){
es[from].eb(to, cap, cost, sz(es[to]));
es[to].eb(from, 0, -cost, sz(es[from])-1);
}
void bellman_ford(int s){
fill(all(h), INF_T);
h[s] = 0;
while(true){
bool update = false;
rep(i, n){
if(h[i] == INF_T) continue;
each(e, es[i]){
if(e.cap > 0 && chmin(h[e.to], h[i]+e.cost)){
update = true;
}
}
}
if(!update) break;
}
}
void dijkstra(int s){
fill(all(d), INF_T);
using P = pair<T, int>;
priority_queue<P, vector<P>, greater<P> > que;
que.emplace(d[s] = 0, s);
while(!que.empty()){
auto [p, i] = que.top(); que.pop();
if(p > d[i]) continue;
rep(j, sz(es[i])){
edge &e = es[i][j];
if(e.cap > 0 && chmin(d[e.to], d[i]+e.cost+h[i]-h[e.to])){
pre_v[e.to] = i, pre_e[e.to] = j;
que.emplace(d[e.to], e.to);
}
}
}
}
T min_cost_flow(int s, int t, T flow){
T ret = 0;
fill(all(h), 0);
//bellman_ford(s);
while(flow > 0){
dijkstra(s);
if(d[t] == INF_T) return -1;
rep(i, sz(es)){
if(h[i] == INF_T || d[i] == INF_T) h[i] = INF_T;
else h[i] += d[i];
}
T f = flow;
for(int now = t; now != s; now = pre_v[now]){
chmin(f, es[pre_v[now]][pre_e[now]].cap);
}
ret += f*h[t], flow -= f;
for(int now = t; now != s; now = pre_v[now]){
edge &e = es[pre_v[now]][pre_e[now]];
e.cap -= f, es[now][e.rev].cap += f;
}
}
return ret;
}
};
int main(){
int N, M;
cin >> N >> M;
Min_Cost_Flow<ll> G(N);
while(M--){
int u, v; ll c, d;
cin >> u >> v >> c >> d; u--, v--;
G.add_edge(u, v, 1, c), G.add_edge(u, v, 1, d);
G.add_edge(v, u, 1, c), G.add_edge(v, u, 1, d);
}
cout << G.min_cost_flow(0, N-1, 2) << '\n';
}
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