Submission #77179

#	Time	Username	Problem	Language	Result	Execution time	Memory
77179		Vardanyan	Commuter Pass (JOI18_commuter_pass)	C++14	0 / 100	460 ms	263168 KiB

commuter_pass

#include <bits/stdc++.h>
using namespace std;
const int N = 200*1000+7;
const long long INF = 100000000000000005;
vector<pair<int,long long> > g[N];
long long dist[N];
long long ans = INF;
int n,m;
int s,t;
int U,V;
vector<vector<int> > all;
bool col[N];
vector<int> now;
void dfs(int v,long long ds = 0){
    now.push_back(v);
    if(v == t){
        all.push_back(now);
        return;
    }
    for(int i = 0;i<g[v].size();i++){
        pair<int,long long> to = g[v][i];
        if(ds+to.second>dist[to.first]) continue;
        if(col[to.first]) continue;
        col[to.first] = 1;
        dfs(to.first,ds+to.second);
        col[to.first] = 0;
    }
}
long long distu[N],distv[N];
int main(){
    scanf("%d%d",&n,&m);
    scanf("%d%d",&s,&t);
    scanf("%d%d",&U,&V);
    for(int i = 0;i<m;i++){
        int x,y;
        long long z;
        scanf("%d%d%lld",&x,&y,&z);
        g[x].push_back({y,z});
        g[y].push_back({x,z});
    }
    priority_queue<pair<long long,int> > pq;
    pq.push({0,s});
    for(int i = 0;i<=n;i++) dist[i] = INF;
    dist[s] = 0;
    while(!pq.empty()){
        pair<long long,int> gag = pq.top();
        pq.pop();
        for(int i = 0;i<g[gag.second].size();i++){
            int to = g[gag.second][i].first;
            if(dist[to]>(-gag.first)+g[gag.second][i].second){
                dist[to] = (-gag.first)+g[gag.second][i].second;
                pq.push({-dist[to],to});
            }
        }
    }
    dfs(s);
  //  if(all.size()>1) assert(0);
    pq.push({0,U});
    for(int i = 0;i<=n;i++) distu[i] = INF;
    distu[U] = 0;
    while(!pq.empty()){
        pair<long long,int> gag = pq.top();
        pq.pop();
        for(int i = 0;i<g[gag.second].size();i++){
            int to = g[gag.second][i].first;
            if(distu[to]>(-gag.first)+g[gag.second][i].second){
                distu[to] = (-gag.first)+g[gag.second][i].second;
                pq.push({-distu[to],to});
            }
        }
    }
    pq.push({0,V});
    for(int i = 0;i<=n;i++) distv[i] = INF;
    distv[V] = 0;
    while(!pq.empty()){
        pair<long long,int> gag = pq.top();
        pq.pop();
        for(int i = 0;i<g[gag.second].size();i++){
            int to = g[gag.second][i].first;
            if(distv[to]>(-gag.first)+g[gag.second][i].second){
                distv[to] = (-gag.first)+g[gag.second][i].second;
                pq.push({-distv[to],to});
            }
        }
    }
    ans = min(distu[V],distv[U]);
    for(int i = 0;i<all.size();i++){
        long long mn = INF;
        long long mnn = INF;
        for(int j = 0;j<all[i].size();j++){
            mn = min(mn,distu[all[i][j]]);
            mnn = min(mnn,distv[all[i][j]]);
        }
        if(mn<INF && mnn<INF)
        ans = min(ans,mn+mnn);
    }
    cout<<ans<<endl;

    /*for(int i = 1;i<=n;i++){
        cout<<i<<" "<<dist[i]<<endl;
    }*/
    return 0;
}

Compilation message (stderr)

commuter_pass.cpp: In function 'void dfs(int, long long int)':
commuter_pass.cpp:20:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0;i<g[v].size();i++){
                   ~^~~~~~~~~~~~
commuter_pass.cpp: In function 'int main()':
commuter_pass.cpp:48:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int i = 0;i<g[gag.second].size();i++){
                       ~^~~~~~~~~~~~~~~~~~~~~
commuter_pass.cpp:64:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int i = 0;i<g[gag.second].size();i++){
                       ~^~~~~~~~~~~~~~~~~~~~~
commuter_pass.cpp:78:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int i = 0;i<g[gag.second].size();i++){
                       ~^~~~~~~~~~~~~~~~~~~~~
commuter_pass.cpp:87:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0;i<all.size();i++){
                   ~^~~~~~~~~~~
commuter_pass.cpp:90:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int j = 0;j<all[i].size();j++){
                       ~^~~~~~~~~~~~~~
commuter_pass.cpp:31:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d",&n,&m);
     ~~~~~^~~~~~~~~~~~~~
commuter_pass.cpp:32:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d",&s,&t);
     ~~~~~^~~~~~~~~~~~~~
commuter_pass.cpp:33:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d",&U,&V);
     ~~~~~^~~~~~~~~~~~~~
commuter_pass.cpp:37:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d%lld",&x,&y,&z);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~

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