#include <bits/stdc++.h>
using namespace std;
typedef pair<int,int> pii;
int n,q;
pii s[1<<20];
pii pos[200001],com_pos[200001];
int jump[200001][18];
map<int,int> com;
void update(int l, int r, int idx, int x, pii node) {
if (x>r || x<l) return;
if (l==r) {
s[idx]=min(s[idx],node);
} else {
int mid=(l+r)/2;
update(l,mid,2*idx,x,node);
update(mid+1,r,2*idx+1,x,node);
s[idx]=min(s[2*idx],s[2*idx+1]);
}
}
pii query(int l, int r, int idx, int x, int y) {
if (x>r || y<l) return pii(INT_MAX,INT_MAX);
if (x<=l && r<=y) return s[idx];
int mid=(l+r)/2;
return min(query(l,mid,2*idx,x,y),query(mid+1,r,2*idx+1,x,y));
}
int main() {
ios_base::sync_with_stdio(0); cin.tie(0);
cin>>n>>q;
for (int i=0; i<1<<18; ++i) s[i]=pii(INT_MAX,INT_MAX);
for (int i=1; i<=n; ++i) {
int st,ed; cin>>st>>ed;
pos[i].first=st;
pos[i].second=ed;
com[st]=1;
com[ed]=1;
}
int cnt=1;
for (auto it=com.begin(); it!=com.end(); ++it) (*it).second=cnt++;
for (int i=1; i<=n; ++i) {
com_pos[i]=pii(com[pos[i].first],com[pos[i].second]);
update(1,2*n,1,com_pos[i].second,pii(com_pos[i].first,i));
}
for (int i=1; i<=n; ++i) jump[i][0]=query(1,2*n,1,com_pos[i].first,com_pos[i].second).second;
for (int i=1; i<17; ++i) {
for (int j=1; j<=n; ++j) {
jump[j][i]=jump[jump[j][i-1]][i-1];
}
}
while (q--) {
int st,ed,cnt=1;
cin>>st>>ed;
if (com_pos[st].second>com_pos[ed].second) cout<<"impossible\n";
else if (st==ed) cout<<"0\n";
else {
} else cout<<1<<"\n";
}
}
}
Compilation message
events.cpp: In function 'int main()':
events.cpp:64:15: error: 'else' without a previous 'if'
64 | } else cout<<1<<"\n";
| ^~~~
events.cpp:57:19: warning: unused variable 'cnt' [-Wunused-variable]
57 | int st,ed,cnt=1;
| ^~~
events.cpp: At global scope:
events.cpp:68:1: error: expected declaration before '}' token
68 | }
| ^
