#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
const int inf = numeric_limits<int> :: max();
struct ST{
vector<pii> t;
int n;
ST(int ns){
n = ns;
t.assign(4 * n, {inf, 0});
}
pii min(pii x, pii y){
if (x.first < y.first){
return x;
}
return y;
}
void upd(int v, int tl, int tr, int& p, pii& k){
if (tl == tr){
t[v] = min(t[v], k);
return;
}
int tm = (tl + tr) / 2, vv = 2 * v;
if (p <= tm){
upd(vv, tl, tm, p, k);
}
else {
upd(vv + 1, tm + 1, tr, p, k);
}
t[v] = min(t[vv], t[vv + 1]);
}
void upd(int p, pii k){
upd(1, 1, n, p, k);
}
pii get(int v, int tl, int tr, int& l, int& r){
if (l > tr || r < tl) return {inf, 0};
if (l <= tl && tr <= r) return t[v];
int tm = (tl + tr) / 2, vv = 2 * v;
return min(get(vv, tl, tm, l, r), get(vv + 1, tm + 1, tr, l, r));
}
pii get(int l, int r){
return get(1, 1, n, l, r);
}
};
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n, q; cin>>n>>q;
vector<int> l(n + 1), r(n + 1);
for (int i = 1; i <= n; i++){
cin>>l[i]>>r[i];
}
vector<int> all;
for (int i = 1; i <= n; i++) all.push_back(l[i]);
for (int i = 1; i <= n; i++) all.push_back(r[i]);
sort(all.begin(), all.end());
int i = 0, cnt = 0;
map<int, int> mp;
while (i < all.size()){
int j = i;
while (j < all.size() && all[i] == all[j]){
j++;
}
mp[all[i]] = ++cnt;
i = j;
}
for (int i = 1; i <= n; i++){
l[i] = mp[l[i]];
r[i] = mp[r[i]];
}
ST T(cnt);
for (int i = 1; i <= n; i++){
T.upd(r[i], {l[i], i});
}
const int lg = (int) ceil(log2(n));
vector<vector<int>> sp(n + 1, vector<int>(lg + 1));
for (int i = 1; i <= n; i++){
sp[i][0] = (T.get(l[i], r[i])).second;
}
for (int k = 1; k <= lg; k++){
for (int i = 1; i <= n; i++){
sp[i][k] = sp[sp[i][k - 1]][k - 1];
}
}
function<void(int, int)> solve = [&](int a, int b){
if (a == b){
cout<<0<<"\n";
return;
}
if (l[b] <= r[a] && r[a] <= r[b]){
cout<<1<<"\n";
return;
}
if (r[b] < r[a] && l[sp[b][lg]] > r[a]){
cout<<"impossible"<<"\n";
return;
}
int out = 1;
for (int i = lg; i >= 0; i--){
if (r[a] < l[sp[b][i]]){
b = sp[b][i];
out += (1 << i);
}
}
out += (a != b);
cout<<out<<"\n";
};
while (q--){
int s, f; cin>>s>>f;
solve(s, f);
}
}
Compilation message
events.cpp: In function 'int main()':
events.cpp:65:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
65 | while (i < all.size()){
| ~~^~~~~~~~~~~~
events.cpp:67:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
67 | while (j < all.size() && all[i] == all[j]){
| ~~^~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
348 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
142 ms |
20604 KB |
Output is correct |
| 2 |
Correct |
157 ms |
20424 KB |
Output is correct |
| 3 |
Correct |
168 ms |
20432 KB |
Output is correct |
| 4 |
Incorrect |
168 ms |
28360 KB |
Output isn't correct |
| 5 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
348 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
