//#pragma GCC optimize("O1")
//#pragma GCC optimize("O2")
//#pragma GCC optimize("O3")
//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("Ofast")
//#pragma GCC target("avx,avx2,fma")
#include <bits/stdc++.h>
using namespace std;
//#define int long long
#define forn(i,n) for (int i=0; i<n; ++i)
#define pb(x) push_back(x);
#define f first
#define s second
void solve() {
int n, m; cin>>n>>m;
vector<pair<int,int>> a(n);
forn(i,n) cin>>a[i].first>>a[i].second;
//forn(i,n) a[i].f=i+1, a[i].s=i+n+1;
vector<vector<int>> adj(n);
if (n<=5000) {
forn(i,n) {
forn(j,n) {
if (i==j) continue;
if (a[j].f<=a[i].s && a[i].s<=a[j].s) adj[i].pb(j);
}
}
} else {
set<pair<int,int>> s;
forn(i,n) s.insert({a[i].s,i});
auto p = s.end(); --p;
for (;;--p) {
auto x=*p; int i=x.s;
auto it = s.upper_bound({a[i].f,-1});
auto z=*it; if (z.f<a[x.s].f) ++it;
while (it!=s.end() && (*it).f<=x.f) {
if ((*it).s!=i) adj[(*it).s].pb(i);
++it;
}
if (p==s.begin()) break;
}
}
vector<vector<int>> dp(min(n,5000),vector<int>(min(n,5000),1e9));
if (n<=5000) {
vector<int> vis(n,0);
forn(i,n) {
vis.assign(n,0);
queue<int> q;
dp[i][i]=0;
q.push(i);
vis[i]=1;
while (!q.empty()) {
int u=q.front(); q.pop();
if (vis[u]) continue;
vis[u]=1;
for (auto v:adj[u]) {
if (!vis[v]) {
vis[v]=1;
dp[i][v]=min(dp[i][v],dp[i][u]+1);
q.push(v);
}
}
}
}
}
//forn(i,n) {
// cout<<i<<": ";
// for (auto x:adj[i]) cout<<x<<' '; cout<<'\n';
//}
forn(i,m) {
int u,v; cin>>u>>v;
--u, --v;
//int u=0, v=min(4999,n-1);
if (n<=5000) {
if (dp[u][v]==-1) cout<<"impossible\n";
else cout<<dp[u][v]<<'\n';
} else {
}
}
}
int32_t main() {
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
solve();
return 0;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
212 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
212 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
212 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
212 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
135 ms |
104640 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
212 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
