#include <bits/stdc++.h>
using namespace std;
int n,q;
typedef pair<int,int> P;
P arr[100000];
vector<int> pr;
const int sz=262144;
P seg[sz*2];
int table[100000][17];
P merge(P a,P b) {
return a>b?a:b;
}
P sum(int l,int r,int node=1,int nodel=0,int noder=sz-1) {
if (r<nodel||l>noder) {
return P(-1,-1);
}
if (l<=nodel&&noder<=r) {
return seg[node];
}
int mid=(nodel+noder)/2;
return merge(sum(l,r,node*2,nodel,mid),sum(l,r,node*2+1,mid+1,noder));
}
void update(int i,P val) {
i+=sz;
seg[i]=val;
while (i>1) {
i/=2;
seg[i]=merge(seg[i*2],seg[i*2+1]);
}
}
int main(void) {
scanf("%d %d",&n,&q);
for(int i=0;i<n;i++) {
scanf("%d %d",&arr[i].first,&arr[i].second);
pr.push_back(arr[i].first);
pr.push_back(arr[i].second);
}
sort(pr.begin(),pr.end());
pr.erase(unique(pr.begin(),pr.end()),pr.end());
for(int i=0;i<n;i++) {
arr[i].first=lower_bound(pr.begin(),pr.end(),arr[i].first)-pr.begin();
arr[i].second=lower_bound(pr.begin(),pr.end(),arr[i].second)-pr.begin();
//printf("%d %d\n",arr[i].first,arr[i].second);
update(arr[i].first,P(arr[i].second,i));
}
memset(table,-1,sizeof(table));
for(int i=0;i<n;i++) {
P val=sum(0,arr[i].second);
//printf("%d %d\n",val.first,val.second);
if (val.first>arr[i].second) {
table[i][0]=val.second;
}
//printf("%d.\n",table[i][0]);
}
for(int j=1;j<17;j++) {
for(int i=0;i<n;i++) {
if (table[i][j-1]!=-1) {
table[i][j]=table[table[i][j-1]][j-1];
}
}
}
for(int i=0;i<q;i++) {
int s,e;
scanf("%d %d",&s,&e);
s--;
e--;
if (s==e) {
printf("0\n");
continue;
}
if (arr[e].second<arr[s].second) {
printf("impossible\n");
continue;
}
if (arr[e].first<=arr[s].second) {
printf("1\n");
continue;
}
int now=s;
int ret=0;
for(int j=16;j>=0;j--) {
int nt=table[now][j];
if (nt!=-1&&arr[nt].second<arr[e].first) {
ret+=(1<<j);
now=nt;
}
}
printf("%d\n",ret+2);
}
}
Compilation message
events.cpp: In function 'int main()':
events.cpp:37:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
37 | scanf("%d %d",&n,&q);
| ~~~~~^~~~~~~~~~~~~~~
events.cpp:39:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
39 | scanf("%d %d",&arr[i].first,&arr[i].second);
| ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
events.cpp:69:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
69 | scanf("%d %d",&s,&e);
| ~~~~~^~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
3 ms |
6996 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
6996 KB |
Output is correct |
2 |
Incorrect |
3 ms |
6996 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
6996 KB |
Output is correct |
2 |
Incorrect |
3 ms |
6996 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
6996 KB |
Output is correct |
2 |
Incorrect |
3 ms |
6996 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
142 ms |
10816 KB |
Output is correct |
2 |
Correct |
163 ms |
10848 KB |
Output is correct |
3 |
Correct |
191 ms |
10776 KB |
Output is correct |
4 |
Incorrect |
132 ms |
11944 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
3 ms |
6996 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |