#include <bits/stdc++.h>
#define md ((l + r) >> 1)
using namespace std;
typedef int64_t ll;
const int N = 200'005;
array<int, 2> a[N];
int bl[18][N], bl2[18][N];
vector<array<int, 2>> st[2 * N], en[2 * N];
struct node {
pair<int, int> mn;
node() {mn = {1e9, -1};}
node(pair<int, int> _mn) {mn = _mn;}
friend node operator+(const node &l, const node &r) {
return min(l.mn, r.mn);
}
} seg[1 << 19];
void upd(int i, int l, int r, int x, pair<int, int> v) {
if (x == l && r == x) {
seg[i].mn = min(seg[i].mn, v);
return;
}
if (r < x || x < l) {
return;
}
upd(i << 1, l, md, x, v);
upd(i << 1 | 1, md + 1, r, x, v);
seg[i] = seg[i << 1] + seg[i << 1 | 1];
}
node get(int i, int l, int r, int s, int e) {
if (s <= l && r <= e) {
return seg[i];
}
if (r < s || e < l) {
return node();
}
return get(i << 1, l, md, s, e) + get(i << 1 | 1, md + 1, r, s, e);
}
int main() {
ios_base::sync_with_stdio(0), cin.tie(0);
int n, q;
cin >> n >> q;
set<int> times;
for (int i = 0; i < n; i++) {
cin >> a[i][0] >> a[i][1];
times.insert(a[i][0]), times.insert(a[i][1]);
}
vector<int> v;
for (auto i : times) {
v.push_back(i);
}
for (int i = 0; i < n; i++) {
st[lower_bound(v.begin(), v.end(), a[i][0]) - v.begin()].push_back({i, a[i][1]});
en[lower_bound(v.begin(), v.end(), a[i][1]) - v.begin()].push_back({i, a[i][1]});
}
multiset<array<int, 2>> s;
for (int i = v.size() - 1; i >= 0; i--) {
for (auto [idx, t] : en[i]) {
s.insert({-t, idx});
}
for (auto [idx, t] : en[i]) {
bl[0][idx] = (*s.begin())[1];
}
for (auto [idx, t] : st[i]) {
s.erase(s.find({-t, idx}));
}
}
for (int j = 1; j < 18; j++) {
for (int i = 0; i < n; i++) {
bl[j][i] = bl[j - 1][bl[j - 1][i]];
}
}
s.clear();
for (int i = 0; i < v.size(); i++) {
st[i].clear();
en[i].clear();
}
for (int i = 0; i < n; i++) {
int pos = lower_bound(v.begin(), v.end(), a[i][1]) - v.begin();
upd(1, 0, v.size() - 1, pos, {a[i][0], i});
}
for (int i = 0; i < n; i++) {
int l = lower_bound(v.begin(), v.end(), a[i][0]) - v.begin();
int r = lower_bound(v.begin(), v.end(), a[i][1]) - v.begin();
bl2[0][i] = get(1, 0, v.size() - 1, l, r).mn.second;
}
for (int j = 1; j < 18; j++) {
for (int i = 0; i < n; i++) {
bl2[j][i] = bl2[j - 1][bl2[j - 1][i]];
}
}
/*
for (int i = 0; i < n; i++) {
cout << bl2[0][i] << ' ';
}
cout << '\n';*/
while (q--) {
int s, e;
cin >> s >> e;
s--, e--;
if (s == e) {
cout << "0\n";
continue;
}
if (a[e][0] <= a[s][1] && a[s][1] <= a[e][1]) {
cout << "1\n";
continue;
}
int ans = 0;
for (int j = 17; j >= 0; j--) {
int New = bl[j][s];
if (!(a[e][0] <= a[New][1] && a[New][1] <= a[e][1]) && a[New][1] <= a[e][1]) {
s = New;
ans += (1 << j);
}
}
if (a[bl[0][s]][1] > a[e][1]) {
for (int j = 17; j >= 0; j--) {
int New = bl2[j][e];
cout << e << ' ' << New << '\n';
if (!(a[New][0] <= a[s][1] && a[s][1] <= a[New][1])) {
e = New;
ans += 1 << j;
}
}
ans++;
e = bl2[0][e];
} else {
ans++;
s = bl[0][s];
}
if (!(a[e][0] <= a[s][1] && a[s][1] <= a[e][1])) {
cout << "impossible\n";
continue;
}
cout << ans + 1 << '\n';
}
return 0;
}
Compilation message
events.cpp: In function 'int main()':
events.cpp:74:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
74 | for (int i = 0; i < v.size(); i++) {
| ~~^~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
10 ms |
51800 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
8 ms |
51800 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
8 ms |
51800 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
8 ms |
51800 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
197 ms |
64396 KB |
Output is correct |
| 2 |
Correct |
202 ms |
64188 KB |
Output is correct |
| 3 |
Correct |
237 ms |
64580 KB |
Output is correct |
| 4 |
Correct |
225 ms |
69748 KB |
Output is correct |
| 5 |
Incorrect |
316 ms |
75724 KB |
Output isn't correct |
| 6 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
10 ms |
51800 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
