oj.uz

Submission #702524

# Submission time Handle Problem Language Result Execution time Memory
702524 2023-02-24T09:49:51 Z 1075508020060209tc Olympic Bus (JOI20_ho_t4) C++14
0 / 100
 65 ms 12208 KB 
//#pragma GCC optimize("O3")
#include<bits/stdc++.h>
using namespace std;
#define int long long
#define X first
#define Y second

int n;int m;
struct edg{
int x;int y;int d;
}es[50005];
vector<int>e[200005];
vector<int>er[200005];

int vis[200005];
int sccid;
int scc[200005];
vector<int>dfn;

void dfs1(int nw){
vis[nw]=1;
for(int i=0;i<e[nw].size();i++){
    int id=e[nw][i];
    int v=es[id].y;
    if(vis[v]){continue;}
    dfs1(v);
}
dfn.push_back(nw);
}

void dfs2(int nw){
scc[nw]=sccid;
for(int i=0;i<e[nw].size();i++){
    int id=e[nw][i];
    int v=es[id].x;
    if(scc[v]){continue;}
    dfs2(v);
}
}

void kosaraju(){

for(int i=1;i<=n;i++){
    if(!vis[i]){
        dfs1(i);
    }
}
sccid=1;
reverse(dfn.begin(),dfn.end());
for(int i=0;i<dfn.size();i++){
    int v=dfn[i];
    if(scc[v]){continue;}
    sccid++;
    dfs2(v);
}


}



signed main(){
cin>>n>>m;
for(int i=1;i<=m;i++){
    int a;int b;int c;int d;
    cin>>a>>b>>c>>d;
    e[a].push_back(i);
    e[b].push_back(i);
    es[i]={a,b,d};
}
kosaraju();

if(scc[1]==scc[n]){
    cout<<0;return 0;
}
int ans=1e18;
int cnt=0;
for(int i=1;i<=n;i++){
    int a=scc[es[i].x];int b=scc[es[i].y];
    if(a==scc[1]&&b==scc[n]){
        cnt++;
        ans=min(ans,es[i].d);
    }
    if(a==scc[n]&&b==scc[1]){
        cnt++;
        ans=min(ans,es[i].d);
    }
}

if(cnt>=2){
    cout<<ans;return 0;
}
cout<<-1;
}

Compilation message

ho_t4.cpp: In function 'void dfs1(long long int)':
ho_t4.cpp:22:14: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   22 | for(int i=0;i<e[nw].size();i++){
      |             ~^~~~~~~~~~~~~
ho_t4.cpp: In function 'void dfs2(long long int)':
ho_t4.cpp:33:14: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   33 | for(int i=0;i<e[nw].size();i++){
      |             ~^~~~~~~~~~~~~
ho_t4.cpp: In function 'void kosaraju()':
ho_t4.cpp:50:14: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   50 | for(int i=0;i<dfn.size();i++){
      |             ~^~~~~~~~~~~

Subtask #1
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 9684 KB Output is correct
2 Correct 6 ms 9700 KB Output is correct
3 Incorrect 6 ms 9708 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #2
0 / 11.0

# Verdict Execution time Memory Grader output
1 Incorrect 65 ms 12208 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 9680 KB Output is correct
2 Correct 5 ms 9684 KB Output is correct
3 Correct 42 ms 11472 KB Output is correct
4 Correct 5 ms 9684 KB Output is correct
5 Correct 53 ms 12080 KB Output is correct
6 Correct 5 ms 9692 KB Output is correct
7 Correct 5 ms 9684 KB Output is correct
8 Incorrect 48 ms 12056 KB Output isn't correct
9 Halted 0 ms 0 KB -

Subtask #4
0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 9684 KB Output is correct
2 Correct 6 ms 9700 KB Output is correct
3 Incorrect 6 ms 9708 KB Output isn't correct
4 Halted 0 ms 0 KB -