結果

問題 No.1301 Strange Graph Shortest Path
ユーザー firiexp
提出日時 2020-11-27 23:46:45
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 285 ms / 3,000 ms
コード長 3,135 bytes
コンパイル時間 1,354 ms
コンパイル使用メモリ 111,448 KB
最終ジャッジ日時 2025-01-16 08:42:24
ジャッジサーバーID
(参考情報)
judge1 / 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
コンパイルメッセージ
main.cpp: In function ‘int main()’:
main.cpp:99:14: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
   99 |         scanf("%d %d %d %d", &u, &v, &c, &d);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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 <algorithm>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <numeric>
#include <bitset>
#include <cmath>
static const int MOD = 1000000007;
using ll = long long;
using u32 = unsigned;
using u64 = unsigned long long;
using namespace std;
template<class T> constexpr T INF = ::numeric_limits<T>::max() / 32 * 15 + 208;
template<typename F, typename C>
struct PrimalDual {
struct edge {
int to; F cap; C cost; int rev;
edge() = default;
edge(int to, F cap, C cost, int rev):to(to), cap(cap), cost(cost), rev(rev) {};
};
vector<vector<edge>> G;
vector<C> potential, min_cost;
vector<int> prevv, preve;
explicit PrimalDual(int n) : G(n), potential(n), min_cost(n), prevv(n), preve(n) {}
void add_edge(int u, int v, F cap, C cost){
G[u].emplace_back(v, cap, cost, G[v].size());
G[v].emplace_back(u, 0, -cost, G[u].size()-1);
}
struct P{
C first; int second;
P(C first,int second):first(first),second(second){}
bool operator<(const P&a) const{return a.first<first;}
};
void dijkstra(int s){
priority_queue<P> Q;
fill(min_cost.begin(),min_cost.end(), INF<C>);
min_cost[s] = 0;
Q.emplace(0, s);
while(!Q.empty()){
P p = Q.top(); Q.pop();
int v = p.second;
if(min_cost[v] < p.first) continue;
for(int i = 0; i < G[v].size(); ++i){
edge &e=G[v][i];
if(e.cap==0) continue;
if(min_cost[v]+e.cost+potential[v]-potential[e.to] < min_cost[e.to]){
min_cost[e.to] = min_cost[v]+e.cost+potential[v]-potential[e.to];
prevv[e.to] = v;
preve[e.to] = i;
Q.emplace(min_cost[e.to], e.to);
}
}
}
}
C flow(int s, int t, F fl, int &ok){
C res = 0;
fill(potential.begin(),potential.end(), 0);
while(fl > 0){
dijkstra(s);
if(min_cost[t] == INF<C>){
ok = 0;
return res;
}
for (int i = 0; i < potential.size(); ++i) {
if(min_cost[i] < INF<C>) potential[i] += min_cost[i];
}
F d = fl;
for(int v = t; v != s; v = prevv[v]){
d = min(d, G[prevv[v]][preve[v]].cap);
}
fl -= d;
res += potential[t]*d;
for(int v = t; v != s; v = prevv[v]){
G[prevv[v]][preve[v]].cap -= d;
G[v][G[prevv[v]][preve[v]].rev].cap += d;
}
}
ok = 1;
return res;
}
};
int main() {
int n, m;
cin >> n >> m;
PrimalDual<int, ll> G(n);
for (int i = 0; i < m; ++i) {
int u, v, c, d;
scanf("%d %d %d %d", &u, &v, &c, &d);
u--; v--;
G.add_edge(u, v, 1, c);
G.add_edge(v, u, 1, c);
G.add_edge(u, v, 1, d);
G.add_edge(v, u, 1, d);
}
int ret = 0;
cout << G.flow(0, n-1, 2, ret) << "\n";
return 0;
}
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