#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
using namespace std;
#ifndef ONLINE_JUDGE
#define dbg(x) cerr << #x <<" "; print(x); cerr << endl;
#else
#define dbg(x)
#endif
#define sz(x) (int)x.size()
#define len(x) (int)x.length()
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define clr(x) (x).clear()
#define uniq(x) x.resize(unique(all(x)) - x.begin());
#define blt __builtin_popcount
#define pb push_back
#define popf pop_front
#define popb pop_back
#define ld long double
#define ll long long
void print(long long t) { cerr << t; }
void print(int t) { cerr << t; }
void print(string t) { cerr << t; }
void print(char t) { cerr << t; }
void print(double t) { cerr << t; }
void print(long double t) { cerr << t; }
void print(unsigned long long t) { cerr << t; }
template <class T, class V> void print(pair <T, V> p);
template <class T> void print(vector <T> v);
template <class T> void print(set <T> v);
template <class T, class V> void print(map <T, V> v);
template <class T> void print(multiset <T> v);
template <class T, class V> void print(T v[], V n) { cerr << "["; for (int i = 0; i < n; i++) { print(v[i]); cerr << " "; } cerr << "]"; }
template <class T, class V> void print(pair <T, V> p) { cerr << "{"; print(p.first); cerr << ","; print(p.second); cerr << "}"; }
template <class T> void print(vector <T> v) { cerr << "[ "; for (T i : v) { print(i); cerr << " "; } cerr << "]"; }
template <class T> void print(set <T> v) { cerr << "[ "; for (T i : v) { print(i); cerr << " "; } cerr << "]"; }
template <class T> void print(multiset <T> v) { cerr << "[ "; for (T i : v) { print(i); cerr << " "; } cerr << "]"; }
template <class T, class V> void print(map <T, V> v) { cerr << "[ "; for (auto i : v) { print(i); cerr << " "; } cerr << "]"; }
template <class T, class V> void print(unordered_map <T, V> v) { cerr << "[ "; for (auto i : v) { print(i); cerr << " "; } cerr << "]"; }
template <class T> void print(deque <T> v) { cerr << "[ "; for (T i : v) { print(i); cerr << " "; } cerr << "]"; }
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
#define nl '\n'
// for random generations
mt19937 myrand(chrono::steady_clock::now().time_since_epoch().count());
// mt19937 myrand(131);
// for grid problems
int dx[8] = { -1,0,1,0,1,-1,1,-1 };
int dy[8] = { 0,1,0,-1,1,1,-1,-1 };
// lowest / (1 << 17) >= 1e5 / (1 << 18) >= 2e5 / (1 << 21) >= 1e6
void fastIO() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr); cout.tie(nullptr);
}
// file in/out
void setIO(string str = "") {
fastIO();
if (str == "input") {
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
}
else {
// freopen("skis.in", "r", stdin);
// freopen("skis.out", "w", stdout);
}
}
// Indexed Set
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
const int N = 2e5 + 10, M = 5e3 + 10, inf = 1e8, LOG = 18;
int n, q, ord[N];
long long down[N][LOG];
struct node {
long long l, r;
long long id;
bool operator<(const node &y) const { return l < y.l; }
};
vector<node> intervals;
struct segTreeMin {
vector<pair<long long, int>> mTree;
int size;
void init(long long n) {
size = 1;
while(size < n) {
size *= 2;
}
mTree.assign(2 * size - 1, {INT64_MAX, -1});
}
void upd(int u, long long v, int ind, int x, int lx, int rx) { // set value at pos u
if(rx - lx == 1) {
mTree[x] = min(mTree[x], make_pair(v, ind));
return;
}
int m = (lx + rx) / 2;
if(u < m) {
upd(u, v, ind, 2 * x + 1, lx, m);
}else {
upd(u, v, ind, 2 * x + 2, m, rx);
}
mTree[x] = min(mTree[2 * x + 1], mTree[2 * x + 2]);
}
void upd(int u, long long v, int ind) {
upd(u, v, ind, 0, 0, size);
}
pair<long long, int> qry (int l, int r, int x, int lx, int rx) { // range queries
if(l >= rx || lx >= r) {
return {INT64_MAX, -1};
}
if(lx >= l && r >= rx) {
return mTree[x];
}
int m = (rx + lx) / 2;
auto s1 = qry(l, r, 2 * x + 1, lx, m);
auto s2 = qry(l, r, 2 * x + 2, m, rx);
return min(s1, s2);
}
auto qry(int l, int r) {
return qry(l, r, 0, 0, size);
}
};
segTreeMin seg_min;
void solve_() {
cin >> n >> q;
vector<int> compress;
for(int i = 1; i <= n; i++) {
int li, ri; cin >> li >> ri;
intervals.push_back({li, ri, i});
//
compress.push_back(li);
compress.push_back(ri);
}
sort(all(compress));
uniq(compress);
sort(all(intervals));
seg_min.init(sz(compress) + 5);
for(int i = 0; i < n; i++) {
intervals[i].l = lower_bound(all(compress), intervals[i].l) - compress.begin() + 1;
intervals[i].r = lower_bound(all(compress), intervals[i].r) - compress.begin() + 1;
seg_min.upd(intervals[i].r, intervals[i].l, i);
ord[intervals[i].id] = i;
}
for(int i = 0; i < n; i++) {
for(int j = 0; j < LOG; j++) {
down[i][j] = -1;
}
}
for(int i = 1; i < n; i++) {
auto ans = seg_min.qry(intervals[i].l, intervals[i].r + 1);
if(ans.first < intervals[i].l) {
down[i][0] = ans.second;
}
}
for(int i = 1; i < LOG; i++) {
for(int j = 0; j < n; j++) {
if(down[j][i - 1] == -1) {
down[j][i] = -1;
continue;
}
down[j][i] = down[down[j][i - 1]][i - 1];
}
}
for(int i = 0; i < n; i++) {
dbg(make_pair(intervals[i].l, intervals[i].r))
}
while(q--) {
int x, y; cin >> x >> y;
x = ord[x], y = ord[y];
if(x == y) {
cout << 0 << '\n';
continue;
}
if(intervals[x].r == intervals[y].r) {
cout << 1 << '\n';
continue;
}
if(intervals[x].r > intervals[y].r) {
cout << "impossible" << '\n';
continue;
}
int curr = y, aa = 0;
for(int i = LOG - 1; i >= 0; i--) {
if(down[curr][i] == -1) continue;
if(intervals[down[curr][i]].l > intervals[x].r) {
curr = down[curr][i];
aa += 1 << i;
}
}
if(down[curr][0] == -1) {
if(intervals[curr].l > intervals[x].r) {
cout << "impossible" << '\n';
} else {
cout << aa + 1 << '\n';
}
} else {
aa += 1;
if(intervals[down[curr][0]].l > intervals[x].r) {
cout << aa + 1 << '\n';
} else {
cout << aa << '\n';
}
}
}
}
int main() {
setIO();
auto solve = [&](int test_case)-> void {
for (int i = 1; i <= test_case; i++) {
solve_();
}
};
int test_cases = 1;
// cin >> test_cases;
solve(test_cases);
return 0;
}
Compilation message
events.cpp: In function 'void setIO(std::string)':
events.cpp:69:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
69 | freopen("input.txt", "r", stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
events.cpp:70:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
70 | freopen("output.txt", "w", stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
1 ms |
332 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
1160 ms |
29944 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
1 ms |
332 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
