結果
問題 |
No.2764 Warp Drive Spacecraft
|
ユーザー |
![]() |
提出日時 | 2024-05-17 22:29:22 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 605 ms / 3,000 ms |
コード長 | 2,547 bytes |
コンパイル時間 | 4,338 ms |
コンパイル使用メモリ | 263,052 KB |
最終ジャッジ日時 | 2025-02-21 15:06:43 |
ジャッジサーバーID (参考情報) |
judge3 / judge1 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 4 |
other | AC * 35 |
ソースコード
#include <stdio.h> #include <bits/stdc++.h> #include <atcoder/all> using namespace atcoder; using mint = modint998244353; using namespace std; #define rep(i,n) for (int i = 0; i < (n); ++i) #define Inf32 1000000001 #define Inf64 1000000000000000001 /** * Author: Simon Lindholm * Date: 2017-04-20 * License: CC0 * Source: own work * Description: Container where you can add lines of the form kx+m, and query maximum values at points x. * Useful for dynamic programming (``convex hull trick''). * Time: O(\log N) * Status: stress-tested */ using ll =long long; struct Line { mutable ll k, m, p; bool operator<(const Line& o) const { return k < o.k; } bool operator<(ll x) const { return p < x; } }; struct LineContainer : multiset<Line, less<>> { // (for doubles, use inf = 1/.0, div(a,b) = a/b) static const ll inf = LLONG_MAX - 1000000000LL; ll div(ll a, ll b) { // floored division return a / b - ((a ^ b) < 0 && a % b); } bool isect(iterator x, iterator y) { if (y == end()) return x->p = inf, 0; if (x->k == y->k) x->p = x->m > y->m ? inf : -inf; else x->p = div(y->m - x->m, x->k - y->k); return x->p >= y->p; } void add(ll k, ll m) { auto z = insert({k, m, 0}), y = z++, x = y; while (isect(y, z)) z = erase(z); if (x != begin() && isect(--x, y)) isect(x, y = erase(y)); while ((y = x) != begin() && (--x)->p >= y->p) isect(x, erase(y)); } ll query(ll x) { assert(!empty()); auto l = *lower_bound(x); return l.k * x + l.m; } }; vector<long long> get_distance(vector<vector<pair<int,long long>>> &E,int s){ int N = E.size(); vector<long long> dist(N,Inf64); dist[s] = 0; priority_queue<pair<long long,int>,vector<pair<long long,int>>,greater<pair<long long,int>>> pq; pq.push({0,s}); while(!pq.empty()){ auto [d,u] = pq.top(); pq.pop(); if(dist[u] !=d )continue; for(auto [v,w]:E[u]){ if(dist[v] > dist[u] + w){ dist[v] = dist[u] + w; pq.push({dist[v],v}); } } } return dist; } int main(){ int N,M; cin>>N>>M; vector<long long> w(N); rep(i,N)cin>>w[i]; vector<vector<pair<int,long long>>> E(N); rep(i,M){ int u,v; long long ww; cin>>u>>v>>ww; u--,v--; E[u].emplace_back(v,ww); E[v].emplace_back(u,ww); //E[v].push_back({u,ww}); } auto x = get_distance(E,0),y = get_distance(E,N-1); long long ans = x[N-1]; LineContainer cht; rep(i,N){ if(x[i]==Inf64)continue; cht.add(-w[i],-x[i]); } if(!cht.empty()){ rep(i,N){ if(y[i]==Inf64)continue; ans = min(ans,-cht.query(w[i]) + y[i]); } } cout<<ans<<endl; return 0; }