This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include<bits/stdc++.h>
#define pb push_back
#define int long long
#define vi vector<int>
#define vvi vector<vector<int>>
#define pii pair<int, int>
#define vpii vector<pair<int, int>>
#define vc vector<char>
#define vb vector<bool>
#define mii map<int,int>
#define f0r(i,n) for(int i=0;i<n;i++)
#define FOR(i,k,n) for(int i=k;i<n;i++)
#define all(v) (v).begin(),(v).end()
#define rall(v) (v).rbegin(),(v).rend()
#define in(a) int a; cin>>a
#define in2(a,b) int a,b; cin>>a>>b
#define in3(a,b,c) int a,b,c; cin>>a>>b>>c
#define in4(a,b,c,d) int a,b,c,d; cin>>a>>b>>c>>d
#define vin(v,n); vi v(n); f0r(i,n){cin>>v[i];}
#define out(a) cout<<a<<'\n'
#define out2(a,b) cout<<a<<' '<<b<<'\n'
#define out3(a,b,c) cout<<a<<' '<<b<<' '<<c<<'\n'
#define out4(a,b,c,d) cout<<a<<' '<<b<<' '<<c<<' '<<d<<'\n'
#define vout(v) cout<<#v<<' '; for(auto u : v){cout<<u<<' ';} cout<<'\n'
#define dout(a) cout<<a<<' '<<#a<<'\n'
#define dout2(a,b) cout<<a<<' '<<#a<<' '<<b<<' '<<#b<<'\n'
#define yn(x); if(x){cout<<"YES"<<'\n';}else{cout<<"NO"<<'\n';}
#define left second
#define right first
const int leg = 1e9 + 7;
const int mod = 998244353;
using namespace std;
signed main(){
	ios::sync_with_stdio(false);
	cin.tie(NULL);
	//ifstream cin(".in");
	//ofstream cout(".out");
	in2(n,q);
	vector<pair<pii,int>> v;
	f0r(i,n){
		in2(a,b);
		v.pb({{b,a},i});
	}
	sort(rall(v));
	vi dex(n);
	f0r(i,n)dex[v[i].second] = i;
	f0r(i,n){
		//out2(v[i].first.first, v[i].first.second);
	}
	vi nxt(n);
	
	f0r(i,n){
		int l = i;
		int r = n-1;
		while(l < r){
			int mid = l + (r - l + 1)/2;
			if(v[i].right.left <= v[mid].right.right){
				l = mid;
			}
			else{
				r = mid - 1;
			}
		}
		
		if(l != i){
			nxt[i] = l;
		}
		else{
			nxt[i] = -1;
		}
	}
	//vout(nxt);
	vvi jmp(n, vi(17));
	f0r(i,n){
		jmp[i][0] = nxt[i];
	}
	FOR(i, 1, 17){
		f0r(j, n){
			if(jmp[j][i-1] == -1)jmp[j][i] = -1;
			else jmp[j][i] = jmp[jmp[j][i-1]][i-1];
		}
	}
	//vout(jmp[0]);
	f0r(i,n){
		//cout<<jmp[i][0]<<' ';
	}
	//out("");
	f0r(i, q){
		in2(a, b);
		if(a == b)out(0);
		else{
			a--;
			b--;
			swap(a,b);
			a = dex[a];
			b = dex[b];
			int goal = v[b].right.right;
			if(v[a].first.left <= goal && goal <= v[a].first.right){
				out(1);
			}
			else{
				//out3(a,b,goal);
				int cnt = 0;
				for(int i = 16; i>=0; i--){
					if(jmp[a][i] != -1){
						if(v[jmp[a][i]].right.left > goal){
							//out("HI");
							cnt += (1 << i);
							a = jmp[a][i];
						}
					}
				}
				
				if(nxt[a] == -1 || !(v[nxt[a]].right.left <= goal && goal <= v[nxt[a]].right.right))out("impossible");
				else out(cnt+2);
			}
			
		}
		
	}
}
| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... |