#include <bits/stdc++.h>
using namespace std;
const int N=1e5+37;
vector<int> adj[N];
int d[N], p[N], vis[N], c[N];
// 1. subtask
signed main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
int n, q; cin>>n>>q;
vector<array<int, 3>> a(n);
for(int i=0; i<n; i++)
{
cin>>a[i][0]>>a[i][1];
a[i][2]=i; p[i]=i;
}
sort(a.begin(), a.end());
for(int i=0; i<n-1; i++)
{
if(a[i+1][0]<=a[i][1]&&a[i+1][1]>=a[i][1])
{
adj[a[i][2]].push_back(a[i+1][2]);
c[a[i+1][2]]++;
}
}
queue<array<int, 3>> qu;
for(int i=0; i<n; i++)
{
if(c[i]==0)
{
qu.push({i, 0, i});
}
}
while(qu.size())
{
int v=qu.front()[0], u=qu.front()[1], par=qu.front()[2];
qu.pop();
d[v]=u; p[v]=par;
if(adj[v].size()) qu.push({adj[v][0], u+1, par});
}
while(q--)
{
int s, e; cin>>s>>e;
s--; e--;
if(p[s]!=p[e]||d[e]<d[s]) cout<<"impossible"<<"\n";
else cout<<d[e]-d[s]<<"\n";
}
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
2644 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
2 ms |
2680 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
2 ms |
2680 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
2 ms |
2680 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
73 ms |
11896 KB |
Output is correct |
2 |
Correct |
82 ms |
11764 KB |
Output is correct |
3 |
Correct |
65 ms |
11764 KB |
Output is correct |
4 |
Correct |
51 ms |
9932 KB |
Output is correct |
5 |
Correct |
67 ms |
12140 KB |
Output is correct |
6 |
Incorrect |
73 ms |
11968 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
2644 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |