Submission #705441

#	Time	Username	Problem	Language	Result	Execution time	Memory
705441		blacktulip	Olympic Bus (JOI20_ho_t4)	C++17	37 / 100	197 ms	12060 KiB

ho_t4

#include <bits/stdc++.h>

using namespace std;

typedef long long lo; 
typedef pair< lo,lo > PII;

#define fi first
#define se second
#define int long long
#define mp make_pair
#define endl "\n"
#define pb push_back
#define fio() ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL)
#define FOR for(int i=1;i<=n;i++)
#define mid ((start+end)/2)
#define ort ((bas+son)/2)

const lo inf = 10000000000000000;
const lo KOK = 100000;
const lo LOG = 30;
const lo li = 100005;
const lo mod = 1000000007;

int n,m,k,flag,t,y[li],z[li],c[li],d[li],dist[1005][1005],cur1[li],value,par[li],ekstra1,ekstra2,ekstra3;
int cev;
bool vis[li],yolda[li],yolda1[li],yasak[li];
string s;
vector<pair<int,pair<int,int>>> v[li],rv[li];

inline int in(){
    int x;
    scanf("%lld",&x);
    return x;
}

inline void sp(bool cont){
	priority_queue<pair<int,int>> pq;
	pq.push({0,1});
	for(int i=1;i<=n;i++){vis[i]=0;cur1[i]=inf;}
	while(pq.size()){
		int node=pq.top().se;
		int co=-pq.top().fi;
		pq.pop();
		if(vis[node])continue;
		vis[node]=1;
		cur1[node]=co;
		for(auto go:v[node]){
			if(!vis[go.fi] && yasak[go.se.se]==0 && go.se.fi+co<cur1[go.fi]){cur1[go.fi]=go.se.fi+co;par[go.fi]=node;pq.push({-co-go.se.fi,go.fi});}
		}
		if(node==ekstra1){
			if(!vis[ekstra2] && co+ekstra3<cur1[ekstra2]){cur1[ekstra2]=ekstra3+co;pq.push({-co-ekstra3,ekstra2});}
		}
	}
	if(cont){value=cur1[n];return ;}
	if(vis[n]==0)return ;
	int node=n;
	while(node!=1){
		for(auto go:rv[node]){
			if(go.fi==par[node]){node=go.fi;yolda[go.se.se]=1;break;}
		}
	}
}

inline void sp1(bool cont){
	priority_queue<pair<int,int>> pq;
	pq.push({0,n});
	for(int i=1;i<=n;i++){vis[i]=0;cur1[i]=inf;}
	while(pq.size()){
		int node=pq.top().se;
		int co=-pq.top().fi;
		pq.pop();
		if(vis[node])continue;
		vis[node]=1;
		cur1[node]=co;
		for(auto go:v[node]){
			if(!vis[go.fi] && yasak[go.se.se]==0 && go.se.fi+co<cur1[go.fi]){cur1[go.fi]=go.se.fi+co;par[go.fi]=node;pq.push({-co-go.se.fi,go.fi});}
		}
		if(node==ekstra1){
			if(!vis[ekstra2] && co+ekstra3<cur1[ekstra2]){cur1[ekstra2]=ekstra3+co;pq.push({-co-ekstra3,ekstra2});}
		}
	}
	if(cont){value=cur1[1];return ;}
	if(vis[1]==0)return ;
	int node=1;
	while(node!=n){
		for(auto go:rv[node]){
			if(go.fi==par[node]){node=go.fi;yolda1[go.se.se]=1;break;}
		}
	}
}

int32_t main(void){
    n=in(),m=in();
    FOR{
		for(int j=1;j<=n;j++){dist[i][j]=inf;}
		dist[i][i]=0;
	}
    for(int i=1;i<=m;i++){
		y[i]=in(),z[i]=in(),c[i]=in(),d[i]=in();
		dist[y[i]][z[i]]=min(dist[y[i]][z[i]],c[i]);
		v[y[i]].pb({z[i],{c[i],i}});
		rv[z[i]].pb({y[i],{c[i],i}});
	}
	for(int i=1;i<=n;i++){
		for(int j=1;j<=n;j++){
			for(int jj=1;jj<=n;jj++){
				dist[j][jj]=min(dist[j][jj],dist[j][i]+dist[i][jj]);
			}
		}
	}
	sp(0);
	sp1(0);
	//~ cout<<"**\n";
	cev=min(inf,dist[1][n]+dist[n][1]);
	for(int i=1;i<=m;i++){
		if(yolda[i]==0 && yolda1[i]==0){
			cev=min(cev,dist[1][n]+dist[n][z[i]]+dist[y[i]][1]+d[i]+c[i]);
			cev=min(cev,dist[n][1]+dist[1][z[i]]+dist[y[i]][n]+d[i]+c[i]);
			cev=min(cev,dist[n][z[i]]+c[i]+dist[y[i]][1]+dist[1][z[i]]+dist[y[i]][n]+d[i]+c[i]);
			continue;
		}
		//~ if(yolda[i] && yolda1[i]){
			yasak[i]=1;
			ekstra1=z[i];
			ekstra2=y[i];
			ekstra3=c[i];
			sp(1);
			yasak[i]=0;
			int val=value;
			ekstra1=z[i];
			ekstra2=y[i];
			ekstra3=c[i];
			yasak[i]=1;
			sp1(1);
			yasak[i]=0;
			cev=min(cev,val+value+d[i]);
			continue;
		//~ }
		if(yolda[i]){
			yasak[i]=1;
			ekstra1=z[i];
			ekstra2=y[i];
			ekstra3=c[i];
			sp(1);
			yasak[i]=0;
			cev=min(cev,min(dist[n][1],dist[n][z[i]]+dist[y[i]][1]+c[i])+value+d[i]);
			continue;
		}
		ekstra1=z[i];
		ekstra2=y[i];
		ekstra3=c[i];
		yasak[i]=1;
		sp1(1);
		yasak[i]=0;
		cev=min(cev,min(dist[1][n],dist[1][z[i]]+dist[y[i]][n]+c[i])+value+d[i]);
	}
	if(cev>=inf)cev=-1;
	printf("%lld\n",cev);
    return 0;
}

Compilation message (stderr)

ho_t4.cpp: In function 'long long int in()':
ho_t4.cpp:33:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   33 |     scanf("%lld",&x);
      |     ~~~~~^~~~~~~~~~~

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