#include <bits/stdc++.h>
using namespace std;
#ifdef DEBUG
#define dbg(...) printf(__VA_ARGS__);
#define getchar_unlocked getchar
#else
#define dbg(...)
#endif
#define sf scanf
#define pf printf
#define fi first
#define se second
#define pb push_back
#define psf push_front
#define ppb pop_back
#define ppf pop_front
#define sz(x) (int)x.size()
#define mnto(x,y) x=min(x,(__typeof__(x))y)
#define mxto(x,y) x=max(x,(__typeof__(x))y)
#define INF 1023456789
#define LINF 1023456789123456789
#define all(x) x.begin(),x.end()
#define lb(x,v) (lower_bound(all(x),v)-x.begin())
#define ub(x,v) (upper_bound(all(x),v)-x.begin())
#define disc(x) sort(all(x));x.resize(unique(all(x))-x.begin());
typedef long long ll;
typedef long double ld;
typedef pair<int,int> ii;
typedef pair<ll,ll> pll;
typedef tuple<int,int,int> iii;
typedef tuple<int,int,int,int> iiii;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<ii> vii;
mt19937 rng(time(0));
#define mod 1000000007
inline int add(int a,int b){
int r=a+b;
while(r>=mod)r-=mod;
while(r<0)r+=mod;
return r;
}
inline int mult(int a,int b){
return (int)(((ll)(a*b))%mod);
}
inline int rd(){
int x=0;
char ch=getchar_unlocked();
while(!(ch&16))ch=getchar();//keep reading while current character is whitespace
while(ch&16){//this will break when ‘\n’ or ‘ ‘ is encountered
x=(x<<3)+(x<<1)+(ch&15);
ch=getchar_unlocked();
}
return x;
}
#define maxn 100005
int n,q,s[maxn],e[maxn];
set<ii> nx[maxn];
int main(){
sf("%d%d",&n,&q);
for(int i=0;i<n;++i){
sf("%d%d",&s[i],&e[i]);
}
for(int i=0;i<n;++i){
for(int j=0;j<n;++j){
if(i==j)continue;
if(s[j]<=e[i]&&e[i]<=e[j]){
nx[i].insert({e[j],j});
}
}
}
for(int i=0;i<q;++i){
int l,r;sf("%d%d",&l,&r);
--l,--r;
int ans=0;
while(l!=r){
if(nx[l].count({e[r],r})){
++ans;break;
}
if(nx[l].empty()||e[r]<(*nx[l].begin()).fi||(*--nx[l].end()).fi==e[l]){
ans=-1;break;
}
auto it=--nx[l].upper_bound({e[r],-1});
l=(*it).se;++ans;
}
if(ans!=-1)pf("%d\n",ans);
else pf("impossible\n");
}
}
Compilation message
events.cpp: In function 'int main()':
events.cpp:68:4: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
68 | sf("%d%d",&n,&q);
| ^
events.cpp:70:5: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
70 | sf("%d%d",&s[i],&e[i]);
| ^
events.cpp:81:13: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
81 | int l,r;sf("%d%d",&l,&r);
| ^
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
4948 KB |
Output is correct |
2 |
Execution timed out |
1579 ms |
8364 KB |
Time limit exceeded |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
4948 KB |
Output is correct |
2 |
Correct |
2 ms |
4948 KB |
Output is correct |
3 |
Correct |
7 ms |
5096 KB |
Output is correct |
4 |
Correct |
6 ms |
5076 KB |
Output is correct |
5 |
Correct |
7 ms |
5020 KB |
Output is correct |
6 |
Execution timed out |
1568 ms |
11944 KB |
Time limit exceeded |
7 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
4948 KB |
Output is correct |
2 |
Correct |
2 ms |
4948 KB |
Output is correct |
3 |
Correct |
7 ms |
5096 KB |
Output is correct |
4 |
Correct |
6 ms |
5076 KB |
Output is correct |
5 |
Correct |
7 ms |
5020 KB |
Output is correct |
6 |
Execution timed out |
1568 ms |
11944 KB |
Time limit exceeded |
7 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
4948 KB |
Output is correct |
2 |
Correct |
2 ms |
4948 KB |
Output is correct |
3 |
Correct |
7 ms |
5096 KB |
Output is correct |
4 |
Correct |
6 ms |
5076 KB |
Output is correct |
5 |
Correct |
7 ms |
5020 KB |
Output is correct |
6 |
Execution timed out |
1568 ms |
11944 KB |
Time limit exceeded |
7 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Execution timed out |
1509 ms |
8228 KB |
Time limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
4948 KB |
Output is correct |
2 |
Execution timed out |
1579 ms |
8364 KB |
Time limit exceeded |
3 |
Halted |
0 ms |
0 KB |
- |