제출 #510212

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
510212		CSQ31	Olympic Bus (JOI20_ho_t4)	C++17	0 / 100	243 ms	262148 KiB

ho_t4

#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
const int MAXN = 5e4+5;
const ll INF = 1e18;
#define sz(a) (int)(a.size())
ll c[MAXN],d[MAXN],dist[MAXN];
int n,m;
array<int,2>par[201];
vector<array<int,2>>g[201],gr[201];
bool block[MAXN],vis[201];
void djikstra(int v,vector<array<int,2>>*g){
	for(int i=1;i<=n;i++)dist[i] = INF,vis[i] = 0;
	dist[v] = 0;
	while(true){
		int u = 0;
		for(int i=1;i<=n;i++)if(dist[i] < dist[u] && !vis[i])u = i;
		if(!u)break;
		vis[u] = 1;
		for(auto x:g[u]){
			if(block[x[1]])continue;
			if(dist[u] + c[x[1]] < dist[x[0]]){
				dist[x[0]] = dist[u] + c[x[1]];
				par[x[0]] = {u,x[1]};
			}
		}
	}
}
vector<int>path;
ll notused[2][201],used[2][201];
int main()
{
	cin>>n>>m;
	ll thonk = 0;
	dist[0] = INF;
	vector<array<int,2>>edge;
	for(int i=0;i<m;i++){
		int v,u;
		cin>>v>>u>>c[i]>>d[i];
		g[v].push_back({u,i});
		gr[u].push_back({v,i});
		edge.push_back({v,u});
	}
	djikstra(1,g);
	thonk+=dist[n];
	for(int i=0;i<m;i++)used[0][i]+=dist[edge[i][1]] + c[i];
	for(int i=0;i<m;i++)notused[0][i] = dist[n];
	if(dist[n] != INF){
		int cur = n;
		while(cur!=1){
			path.push_back(par[cur][1]);
			cur = par[cur][0];
		}
		for(int x:path){
			block[x] = 1;
			djikstra(1,g);
			used[0][x] = dist[n];	
			block[x] = 0;
		}
	}
	djikstra(n,gr);
	for(int i=0;i<m;i++)used[0][i]+=dist[edge[i][0]];
	
	djikstra(n,g);
	thonk+=dist[1];
	for(int i=0;i<m;i++)used[1][i]+=dist[edge[i][1]] + c[i];
	for(int i=0;i<m;i++)notused[1][i] = dist[1];
	if(dist[1] != INF){
		int cur = n;
		while(cur!=1){
			path.push_back(par[cur][1]);
			cur = par[cur][0];
		}
		for(int x:path){
			block[x] = 1;
			djikstra(n,g);
			used[1][x] = dist[1];	
			block[x] = 0;
		}
	}
	djikstra(1,gr);
	for(int i=0;i<m;i++)used[1][i]+=dist[edge[i][0]];
	
	ll ans =  min(INF,thonk);
	for(int i=0;i<m;i++){
		ans = min(ans,min(used[0][i],notused[0][i]) + min(used[1][i],notused[1][i]) + d[i]);
	}
	if(ans == INF)ans = -1;
	cout<<ans;
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 11
• Subtask 3: 0 / 21
• Subtask 4: 0 / 63