#include<bits/stdc++.h>
using namespace std;
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#define N 100005
struct A{
int s,e,id;
bool operator<(const A& o)const{
if(e!=o.e)return e>o.e;
return s<o.s;
}
};
int s[N],e[N],dep[N],nxt[20][N],mi;
vector<int> g[N];
vector<A> edge;
void dfs(int s){
for(auto x:g[s]){
dep[x]=dep[s]+1;
dfs(x);
}
}
int main(){
int n,q,i,j,a,b;
scanf("%d %d",&n,&q);
for(i=1;i<=n;i++){
scanf("%d %d",&s[i],&e[i]);
edge.push_back({s[i],e[i],i});
}
sort(edge.begin(),edge.end());
mi=1e9;
for(auto [s,e,id]:edge){
if(mi<=e)nxt[0][id]=i;
if(s<mi)mi=s,i=id;
}
for(i=1;i<=n;i++)g[nxt[0][i]].push_back(i);
dfs(0);
for(i=1;i<20;i++)for(j=1;j<=n;j++)nxt[i][j]=nxt[i-1][nxt[i-1][j]];
while(q--){
scanf("%d %d",&a,&b);
if(s[a]==s[b]&&e[a]==e[b])printf("1\n");
else if(dep[a]<dep[b])printf("impossible\n");
else{
int dif=dep[a]-dep[b];
for(i=0;i<20;i++)if(dif&(1<<i))a=nxt[i][a];
if(a==b)printf("%d\n",dif);
else printf("impossible\n");
}
}
return 0;
}
Compilation message
events.cpp: In function 'int main()':
events.cpp:28:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
28 | scanf("%d %d",&n,&q);
| ~~~~~^~~~~~~~~~~~~~~
events.cpp:30:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
30 | scanf("%d %d",&s[i],&e[i]);
| ~~~~~^~~~~~~~~~~~~~~~~~~~~
events.cpp:43:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
43 | scanf("%d %d",&a,&b);
| ~~~~~^~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
2 ms |
2644 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
2 ms |
2644 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
2 ms |
2644 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
2 ms |
2644 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
113 ms |
19292 KB |
Output is correct |
2 |
Correct |
118 ms |
19272 KB |
Output is correct |
3 |
Correct |
148 ms |
19356 KB |
Output is correct |
4 |
Correct |
71 ms |
14416 KB |
Output is correct |
5 |
Incorrect |
147 ms |
18240 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
2 ms |
2644 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |