제출 #707747

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
707747		vjudge1	Olympic Bus (JOI20_ho_t4)	C++14	100 / 100	553 ms	4412 KiB

ho_t4

#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<int,int>
#define f first
#define s second
#define all(x) x.begin(),x.end() 
#define _ ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
 
void setIO(string s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}
 
struct edge{
    int a,b,c,d;
};
 
const int mxn=205;
vector<tuple<int,int,int>> adj[2][mxn];
int n,m;
ll dist[5][mxn];
vector<int> from[4][mxn];
 
void dijk(int type,int rot,int st,int en){
    dist[type][st]=0;
    priority_queue<pair<ll,int>,vector<pair<ll,int>>,greater<pair<ll,int>>> pq;
    pq.push({0,st});
    while(!pq.empty()){
        auto tmp=pq.top();
        pq.pop();
        ll len=tmp.f;
        int v=tmp.s;
        if(len!=dist[type][v]) continue;
        for(auto u:adj[rot][v]){
            int nxt,w,id;
            tie(nxt,w,id)=u;
            if(dist[type][v]+1ll*w<dist[type][nxt]){
                dist[type][nxt]=dist[type][v]+1ll*w;
                from[type][nxt]=from[type][v];
                from[type][nxt].push_back(id);
                pq.push({dist[type][nxt],nxt});
            }
        }
    }
    sort(all(from[type][en]));
}
 
ll dijk2(int type,int rot,int st,int en,int ban){
    for(int j=1;j<=n;j++){
        dist[type][j]=0x3f3f3f3f3f3f3f3f;
    }
    dist[type][st]=0;
    priority_queue<pair<ll,int>,vector<pair<ll,int>>,greater<pair<ll,int>>> pq;
    pq.push({0,st});
    while(!pq.empty()){
        auto tmp=pq.top();
        pq.pop();
        ll len=tmp.f;
        int v=tmp.s;
        if(len!=dist[type][v]) continue;
        for(auto u:adj[rot][v]){
            int nxt,w,id;
            tie(nxt,w,id)=u;
            if(id==ban) continue;
            if(dist[type][v]+1ll*w<dist[type][nxt]){
                dist[type][nxt]=dist[type][v]+1ll*w;
                pq.push({dist[type][nxt],nxt});
            }
        }
    }
    return dist[type][en];
}
 
int main() {_
    //setIO("wayne");
    cin>>n>>m;
    edge E[m];
    for(int i=0;i<m;i++){
        int a,b,c,d;
        cin>>a>>b>>c>>d;
        E[i]={a,b,c,d};
        adj[0][a].push_back({b,c,i});
        adj[1][b].push_back({a,c,i});
    }
    memset(dist,0x3f3f3f3f,sizeof(dist));
    dijk(0,0,1,n);
    dijk(1,1,1,n);
    dijk(2,0,n,1);
    dijk(3,1,n,1);
    ll ans=dist[0][n]+dist[2][1];
    for(int i=0;i<m;i++){
        ll a,b,c,d;
        a=E[i].a,b=E[i].b,c=E[i].c,d=E[i].d;
        ll ans1;
        ll ans2;
        {
            if(upper_bound(all(from[0][n]),i)-lower_bound(all(from[0][n]),i)>=1){
                ans1=dijk2(4,0,1,n,i);
            }
            else{
                ans1=min(dist[0][b]+c+dist[3][a],dist[0][n]);
            }
        }
        {
            if(upper_bound(all(from[2][1]),i)-lower_bound(all(from[2][1]),i)>=1){
                ans2=dijk2(4,0,n,1,i);
            }
            else{
                ans2=min(dist[2][b]+c+dist[1][a],dist[2][1]);
            }
        }
        ans=min(ans,ans1+ans2+d);
    }
    cout<<(ans>=0x3f3f3f3f3f3f3f3f?-1:ans);
    return 0;
}
//maybe its multiset not set

컴파일 시 표준 에러 (stderr) 메시지

ho_t4.cpp: In function 'void setIO(std::string)':
ho_t4.cpp:12:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   12 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ho_t4.cpp:13:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   13 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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