#include <bits/stdc++.h>
using namespace std;
typedef pair<int, int> pii;
constexpr int INF = 1e9;
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int n, q;
cin >> n >> q;
vector<pair<pii, int>> events(n);
vector<int> start(n), end(n);
map<int, int> mp;
for(int i = 0; i < n; i++) {
cin >> start[i] >> end[i];
events[i].first = {end[i], start[i]};
mp[start[i]] = mp[end[i]] = 1;
events[i].second = i;
}
int t = 0;
for(auto& [x, cmp] : mp)
cmp = t++;
sort(events.begin(), events.end());
int N = 1 << 32 - __builtin_clz(t - 1);
vector<pii> st(2 * N, {INF, -1});
vector<int> parent(n), jump(n), depth(n);
for(int i = 0; i < n; i++) {
int e = events[i].first.first, s = events[i].first.second;
pii ans = {INF, -1};
for(int l = N + mp[s], r = 2 * N; l < r; l >>= 1, r >>= 1) {
if(l & 1) ans = min(ans, st[l++]);
if(r & 1) ans = min(ans, st[--r]);
}
int v = events[i].second;
if(ans.second == -1 || ans.first >= s)
jump[v] = parent[v] = v;
else {
int p = parent[v] = ans.second;
depth[v] = depth[p] + 1;
if(depth[p] - depth[jump[p]] == depth[jump[p]] - depth[jump[jump[p]]])
jump[v] = jump[jump[p]];
else
jump[v] = p;
}
for(int j = N + mp[e]; j > 0; j >>= 1)
st[j] = min(st[j], {mp[s], v});
}
while(q--) {
int x, y;
cin >> x >> y;
x--;
y--;
int d = depth[y];
while(x != y && parent[y] != y && start[parent[y]] >= start[x]) {
if(start[jump[y]] > start[x])
y = jump[y];
else
y = parent[y];
}
if(end[x] >= start[y] && end[x] <= end[y])
cout << (x!=y) + d - depth[y] << '\n';
else
cout << "impossible\n";
}
}
Compilation message
events.cpp: In function 'int main()':
events.cpp:22:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
22 | for(auto& [x, cmp] : mp)
| ^
events.cpp:25:21: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
25 | int N = 1 << 32 - __builtin_clz(t - 1);
| ~~~^~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
160 ms |
13964 KB |
Output is correct |
3 |
Correct |
170 ms |
14004 KB |
Output is correct |
4 |
Correct |
178 ms |
13816 KB |
Output is correct |
5 |
Incorrect |
160 ms |
14424 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
344 KB |
Output is correct |
2 |
Correct |
1 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
348 KB |
Output is correct |
4 |
Correct |
1 ms |
348 KB |
Output is correct |
5 |
Correct |
1 ms |
348 KB |
Output is correct |
6 |
Incorrect |
1 ms |
352 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
344 KB |
Output is correct |
2 |
Correct |
1 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
348 KB |
Output is correct |
4 |
Correct |
1 ms |
348 KB |
Output is correct |
5 |
Correct |
1 ms |
348 KB |
Output is correct |
6 |
Incorrect |
1 ms |
352 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
344 KB |
Output is correct |
2 |
Correct |
1 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
348 KB |
Output is correct |
4 |
Correct |
1 ms |
348 KB |
Output is correct |
5 |
Correct |
1 ms |
348 KB |
Output is correct |
6 |
Incorrect |
1 ms |
352 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
170 ms |
13912 KB |
Output is correct |
2 |
Correct |
172 ms |
13912 KB |
Output is correct |
3 |
Correct |
160 ms |
13912 KB |
Output is correct |
4 |
Correct |
141 ms |
21088 KB |
Output is correct |
5 |
Correct |
145 ms |
14168 KB |
Output is correct |
6 |
Correct |
206 ms |
20932 KB |
Output is correct |
7 |
Correct |
198 ms |
20772 KB |
Output is correct |
8 |
Correct |
164 ms |
20968 KB |
Output is correct |
9 |
Correct |
147 ms |
19016 KB |
Output is correct |
10 |
Correct |
217 ms |
20556 KB |
Output is correct |
11 |
Correct |
176 ms |
20304 KB |
Output is correct |
12 |
Correct |
233 ms |
20528 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
160 ms |
13964 KB |
Output is correct |
3 |
Correct |
170 ms |
14004 KB |
Output is correct |
4 |
Correct |
178 ms |
13816 KB |
Output is correct |
5 |
Incorrect |
160 ms |
14424 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |