Submission #1124862

#	Time	Username	Problem	Language	Result	Execution time	Memory
1124862		the_ZHER	Commuter Pass (JOI18_commuter_pass)	C++20	0 / 100	124 ms	21840 KiB

commuter_pass

#include <bits/stdc++.h>
#define int long long
#define boost ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
using namespace std;
const int N = 2e5 + 4;
const int inf = 1e17;
const int mod=998244353;
struct edge{
    int x,y,c;
};
bool cmp(edge a,edge b){
    return a.c<=b.c;
}
vector<pair<int,int> >v[N];
vector<int>v1[N];
vector<edge>v2;
int pr[N];
int get(int x){
    if(pr[x]==x){
        return x;
    }
    return pr[x]=get(pr[x]);
}
void unio(int x,int y){
    int a=get(x);
    int b=get(y);
    if(a==b){
        return ;
    }
    pr[a]=b;
}
int us[N];
int us1[N];
void dfs(int n,int pre){
    us[n]=pre;
    for(int i=0;i<v[n].size();i++){
        if(v[n][i].first!=pre){
            dfs(v[n][i].first,n);
        }
    }
}
void dfs1(int n,int pre,int cena){
    us1[n]=cena;
    for(int i=0;i<v[n].size();i++){
        if(v[n][i].first!=pre){
            int cnt=v[n][i].second;
            for(int j=0;j<v1[n].size();j++){
                if(v[n][i].first==v1[n][j]){
                    cnt=0;
                }
            }
            dfs1(v[n][i].first,n,cena+cnt);
        }
    }
}
signed main(){
//freopen("input.txt", "r", stdin);
//freopen("output.txt", "w", stdout);
    boost 
    int n,m;
    cin>>n>>m;
    int s,t,u,w;
    cin>>s>>t>>u>>w;
    for(int i=0;i<m;i++){
        int x,y,c;
        cin>>x>>y>>c;
        v2.push_back({x,y,c});
    }
    for(int i=1;i<=n;i++){
        pr[i]=i;
    }
    reverse(v2.begin(),v2.end());
    sort(v2.begin(),v2.end(),cmp);
    for(int i=0;i<v2.size();i++){
    int a=get(v2[i].x);
    int b=get(v2[i].y);
    int x=v2[i].x;
    int y=v2[i].y;
    int c=v2[i].c;
    if(a!=b){
        v[x].push_back({y,c});
        v[y].push_back({x,c});
        unio(x,y);
    }  
    }
    dfs(s,0);
    int x=t;
    while(x!=s){
        v1[x].push_back(us[x]);
        v1[us[x]].push_back(x);
        x=us[x];
    }
    dfs1(u,0,0);
    cout<<us1[w];
}

• Subtask 1: 0 / 16
• Subtask 2: 0 / 15
• Subtask 3: 0 / 24
• Subtask 4: 0 / 45