| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 1295291 | hihihihaw | Event Hopping (BOI22_events) | C++20 | 0 ms | 0 KiB |
#pragma GCC optimize("O3,unroll-loops")
#include <bits/stdc++.h>
using namespace std;
#define int long long
#define ll long long
#define pb push_back
#define pii pair<int,int>
#define sz(v) (int)v.size()
#define fi first
#define se second
#define INF 1223372036854775807
#define INF2 122337203
#define MOD 998244353
#define cint(x) int x;cin>>x;
#define cinarr(a,n) int a[n];for (int i=0;i<n;i++) cin>>a[i];
#define coutarr(a) for (auto d:a)cout<<d<<" "; cout<<endl;
#define coutarrD(a) for (auto d:a) cout<<d.fi<<","<<d.se<<" "; cout<<endl;
#define BERKAY_TUP ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL)
#define endl '\n'
#define ld long double
#define mid (start+end)/2
#define vvi vector<vector<int>>
int t=1;
int interactive=0;
int usaco=0;
int testCase=0;
void solve(){
int n,q;
cin>>n>>q;
vector<pii> v;
for (int i=0;i<n;i++){
int x,y;
cin>>x>>y;
v.pb({x,y});
}
vector<int> edges[1023];
for (int i=0;i<n;i++){
for (int j=0;j<n;j++){
if (i==j) continue;
if (v[j].se>=v[i].se && v[i].se>=v[j].fi) edges[i].pb(j);
}
}
while (q--){
int a,b;
cin>>a>>b;
int dist[1023];
bool seen[1023]=false;
queue<int> q;
q.push(a);
dist[a]=0;
while (!q.empty()){
int c=q.front();
q.pop();
seen[c]=true;
for (int d:edges[c]){
if (!seen[d]){
q.push(d);
dist[d]=dist[c]+1;
}
}
}
if (!seen[b]){
cout<<"impossible"<<endl;
}
else{
cout<<dist[b]<<endl;
}
}
}
int32_t main(){
BERKAY_TUP;
if (usaco){
freopen("team.in", "r", stdin);
freopen("team.out", "w", stdout);
}
if (!interactive){
#ifdef Local
freopen("in.txt", "r", stdin);
freopen("out2.txt", "w", stdout);
//freopen("wormsort.out", "w", stdout);
#endif
}
if (t==1) solve();
else{
cin>>t;
while (t--){testCase++;solve();}
}
return 0;
}