#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];
array<int, 2> st[N*8];
map<int, int> mp;
// 1. subtask
void update(int v, int l, int r, int pos, array<int, 2> val)
{
if(l==r&&l==pos) st[v]=max(st[v], val);
else if(l>r) return;
else
{
int mid=(l+r)/2;
if(pos<=mid) update(v*2, l, mid, pos, val);
else update(v*2+1, mid+1, r, pos, val);
st[v]=max(st[v*2+1], st[v*2]);
}
}
array<int, 2> get(int v, int l, int r, int tl, int tr)
{
if(r<l) return {0, 0};
if(l>tr||r<tl) return {0, 0};
if(l>=tl&&r<=tr) return st[v];
if(l==r) return {0, 0};
int mid=(l+r)/2;
return max(get(v*2, l, mid, tl, tr), get(v*2+1, mid+1, r, tl, tr));
}
signed main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
int n, q; cin>>n>>q;
vector<array<int, 3>> a(n);
vector<int> x;
for(int i=0; i<n; i++)
{
cin>>a[i][0]>>a[i][1];
a[i][2]=i; p[i]=i;
x.push_back(a[i][0]);
x.push_back(a[i][1]);
}
sort(x.begin(), x.end());
int cnt=1;
for(auto i: x)
{
if(mp.count(i)==0) mp[i]=cnt, cnt++;
}
for(int i=0; i<n; i++)
{
a[i][0]=mp[a[i][0]];
a[i][1]=mp[a[i][1]];
}
sort(a.begin(), a.end());
for(int i=n-1; i>=0; i--)
{
auto v=get(1, 0, n*2, a[i][0], a[i][1]);
if(v[0]>=a[i][1])
{
adj[a[i][2]].push_back(v[1]);
c[v[1]]++;
}
update(1, 0, n*2, a[i][0], {a[i][1], a[i][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";
}
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
2644 KB |
Output is correct |
2 |
Correct |
215 ms |
16272 KB |
Output is correct |
3 |
Correct |
175 ms |
16284 KB |
Output is correct |
4 |
Correct |
178 ms |
16244 KB |
Output is correct |
5 |
Incorrect |
182 ms |
16880 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
1 ms |
2644 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
1 ms |
2644 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
1 ms |
2644 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
197 ms |
16344 KB |
Output is correct |
2 |
Correct |
184 ms |
16324 KB |
Output is correct |
3 |
Correct |
178 ms |
16232 KB |
Output is correct |
4 |
Correct |
192 ms |
21224 KB |
Output is correct |
5 |
Correct |
188 ms |
16692 KB |
Output is correct |
6 |
Incorrect |
226 ms |
23512 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
2644 KB |
Output is correct |
2 |
Correct |
215 ms |
16272 KB |
Output is correct |
3 |
Correct |
175 ms |
16284 KB |
Output is correct |
4 |
Correct |
178 ms |
16244 KB |
Output is correct |
5 |
Incorrect |
182 ms |
16880 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |