#include <bits/stdc++.h>
using namespace std;
#define int long long
vector<vector<pair<int,int>>>g(3e5+5);
vector<long long>dp2(3e5+5,-1);
vector<long long>dp(3e5+5,-1);
signed main()
{
// freopen("5-10.in", "r", stdin);
int n,m;
cin >> n>>m;
// cin >> n >> m;
vector<pair<int,int>>e(m+1);
for(int i = 1;i<=m;i++)
{
int a,b,w;
cin >> a >> b >> w;
//cout << 'o';
g[a].push_back({b,i});
g[b].push_back({a,i});
e[i] = {a,b};
//cout << 'o';
}
//dfs();
dp[1] =0;
queue<int>q;
q.push(1);
while(!q.empty())
{
int v = q.front();
q.pop();
for(auto u : g[v])
{
if(dp[u.first] == -1)
{
q.push(u.first);
dp[u.first] = dp[v] + 1;
}
}
}
dp2[n] =0;
//queue<int>q;
q.push(n);
while(!q.empty())
{
int v = q.front();
q.pop();
for(auto u : g[v])
{
if(dp2[u.first] == -1)
{
q.push(u.first);
dp2[u.first] = dp2[v] + 1;
}
}
}
int mn = 1e9+5;
int num = 0;
int mn2 = 1e9+5;
int s =1;
for(int i = 1;i<=m;i++)
{
int u = e[i].first;
int v = e[i].second;
if((dp[v] == mn && dp2[u]== mn2) || (dp2[v] == mn2 && dp[u]== mn))
{
num++;
}
if(dp[v] + dp2[u]+1 <mn+mn2+1)
{
mn = dp[v];
mn2 = dp2[u];
num = 1;
}
if(i==m && (dp[u] + dp2[v]+1 <mn+mn2+1))
{
num++;
s= 0;
}
// cout << dp[i.first] + dp2[i.second]+1 << '\n';
}
cout << mn+mn2 + ((num == 1)&& !s);
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
6 ms |
12188 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
6 ms |
12188 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
294 ms |
39528 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
284 ms |
40012 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
223 ms |
37204 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
223 ms |
37204 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
6 ms |
12188 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |