oj.uz

Submission #588853

# Submission time Handle Problem Language Result Execution time Memory
588853 2022-07-04T06:36:28 Z Arnch Event Hopping (BOI22_events) C++17
20 / 100
 394 ms 59336 KB 
// oooo
/*
 har chi delet mikhad bebar ~
 gitar o ba khodet nabar! ~
 ;Amoo_Hasan;
*/

#include<bits/stdc++.h>
//#pragma GCC optimize("O3,no-stack-protector,unroll-loops")
//#pragma GCC target("avx2,fma")

using namespace std;

typedef long long ll;
typedef long double ld;

#define Sz(x) int((x).size())
#define All(x) (x).begin(), (x).end()
#define wtf(x) cout<<#x <<" : " <<x <<endl
//#define endl '\n'

constexpr ll inf = 1e18, N = 1e6 + 10, Log = 30;

int n, q, s[N], e[N];
int val[N], par[N][Log], rpar[N][Log];

void Compress() {
	vector<int> com;
	for(int i = 0; i < n; i++) {
		com.push_back(s[i]), com.push_back(e[i]);
	}
	sort(All(com)), com.erase(unique(All(com)), com.end());
	for(int i = 0; i < n; i++) {
		s[i] = lower_bound(All(com), s[i]) - com.begin();
		e[i] = lower_bound(All(com), e[i]) - com.begin();
	}
}

struct node {
	int cnt;
	node() {
		cnt = -1;
	}
};
struct Seg {
	node x[N << 2];
	int type;
	Seg(int dio) {
		type = dio;
	}
	void build(int l, int r, int v) {
		x[v].cnt = -1;
		if(r - l < 2) return;
		int mid = (l + r) >> 1;
		build(l, mid, 2 * v), build(mid, r, 2 * v + 1);
	}
	node merge(node a, node b) {
		node res = a;
		if(type == 0) {
			if(b.cnt != -1 && (res.cnt == -1 || e[b.cnt] > e[res.cnt])) res = b;
			return res;
		} else {
			if(b.cnt != -1 && (res.cnt == -1 || e[b.cnt] < e[res.cnt])) res = b;
			return res;
		}
	}
	void change(int l, int r, int ind, int val, int v) {
		if(r - l < 2) {
			if(type == 0) {
				if(x[v].cnt == -1 || e[x[v].cnt] < e[val]) 
					x[v].cnt = val;
			} else {
				if(x[v].cnt == -1 || e[x[v].cnt] > e[val]) 
					x[v].cnt = val;
			}
			return;
		}
		int mid = (l + r) >> 1;
		if(ind < mid) change(l, mid, ind, val, 2 * v);
		else change(mid, r, ind, val, 2 * v + 1);
		x[v] = merge(x[2 * v], x[2 * v + 1]);
	}
	node get(int l, int r, int s, int e, int v) {
		node res;
		if(r <= s || l >= e) return res;
		if(l >= s && r <= e) return x[v];
		int mid = (l + r) >> 1;
		return merge(get(l, mid, s, e, 2 * v), get(mid, r, s, e, 2 * v + 1));
	}
} S(0), E(1);

void Pre1() {
	for(int i = 0; i < n; i++) {
		S.change(0, 2 * n, s[i], i, 1);
	}
	for(int i = 0; i < n; i++) {
		int pos = S.get(0, 2 * n, s[i], e[i] + 1, 1).cnt;
		if(pos != -1 && e[pos] > e[i]) par[i][0] = pos;
		else par[i][0] = -1;
	}
	
	for(int lg = 1; lg < Log; lg++) {
		for(int i = 0; i < n; i++) {
			if(par[i][lg - 1] == -1 || par[par[i][lg - 1]][lg - 1] == -1) {
				par[i][lg] = -1; continue;
			}
			par[i][lg] = par[par[i][lg - 1]][lg - 1];
		}
	}
}
void Pre2() {
	E.build(0, 2 * n, 1);
	for(int i = 0; i < n; i++) {
		E.change(0, 2 * n, e[i], i, 1);
	}
	for(int i = 0; i < n; i++) {
		int pos = E.get(0, 2 * n, s[i], e[i] + 1, 1).cnt;
		if(pos != -1 && s[pos] < s[i]) rpar[i][0] = pos;
		else rpar[i][0] = -1;
	}

	for(int lg = 1; lg < Log; lg++) {
		for(int i = 0; i < n; i++) {
			if(rpar[i][lg - 1] == -1 || rpar[rpar[i][lg - 1]][lg - 1] == -1) {
				rpar[i][lg] = -1; continue;
			}
			rpar[i][lg] = rpar[rpar[i][lg - 1]][lg - 1];
		}
	}
}

int main() {
    ios :: sync_with_stdio(0), cin.tie(0);

	cin >>n >>q;
	for(int i = 0; i < n; i++) {
		cin >>s[i] >>e[i];
	}
	Compress();

	Pre1();
	Pre2();

	for(int i = 0; i < q; i++) {
		int x, y; cin >>x >>y;
		x--, y--;

		if(x != y && e[x] > e[y]) {
			cout<<"impossible" <<endl;
			continue;
		}
		if(x == y) {
			cout<<0 <<endl;
			continue;
		}
		if(e[x] >= s[y] && e[x] <= e[y]) {
			cout<<1 <<endl;
			continue;
		}
		
		int t = 0;
		for(int lg = Log - 1; lg >= 0; lg--) {
			if(par[x][lg] == -1) continue;
			if(e[par[x][lg]] < s[y]) {
				x = par[x][lg];
				t += (1 << lg);
			}
		}
		if(par[x][0] != -1 && e[par[x][0]] <= e[y]) {
			cout<<t + 2 <<endl;
			continue;
		}
		for(int lg = Log - 1; lg >= 0; lg--) {
			if(rpar[y][lg] == -1) continue;
			if(s[rpar[y][lg]] > e[x]) {
				y = rpar[y][lg];
				t += (1 << lg);
			}
		}
		if(rpar[y][0] != -1 && s[rpar[y][0]] <= e[x]) {
			cout<<t + 1 <<endl;
			continue;
		}
		cout<<"impossible" <<endl;
	}

    return 0;
}

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 31572 KB Output is correct
2 Correct 330 ms 56572 KB Output is correct
3 Correct 346 ms 56600 KB Output is correct
4 Correct 394 ms 56608 KB Output is correct
5 Incorrect 369 ms 58156 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 31656 KB Output is correct
2 Correct 14 ms 31572 KB Output is correct
3 Correct 13 ms 31828 KB Output is correct
4 Correct 13 ms 31828 KB Output is correct
5 Incorrect 14 ms 31828 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 31656 KB Output is correct
2 Correct 14 ms 31572 KB Output is correct
3 Correct 13 ms 31828 KB Output is correct
4 Correct 13 ms 31828 KB Output is correct
5 Incorrect 14 ms 31828 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 31656 KB Output is correct
2 Correct 14 ms 31572 KB Output is correct
3 Correct 13 ms 31828 KB Output is correct
4 Correct 13 ms 31828 KB Output is correct
5 Incorrect 14 ms 31828 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #5
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 350 ms 56528 KB Output is correct
2 Correct 337 ms 56616 KB Output is correct
3 Correct 368 ms 56540 KB Output is correct
4 Correct 350 ms 57732 KB Output is correct
5 Correct 374 ms 57836 KB Output is correct
6 Correct 385 ms 57384 KB Output is correct
7 Correct 391 ms 57120 KB Output is correct
8 Correct 385 ms 59336 KB Output is correct
9 Correct 259 ms 56492 KB Output is correct
10 Correct 358 ms 57996 KB Output is correct
11 Correct 357 ms 57756 KB Output is correct
12 Correct 368 ms 57888 KB Output is correct

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 31572 KB Output is correct
2 Correct 330 ms 56572 KB Output is correct
3 Correct 346 ms 56600 KB Output is correct
4 Correct 394 ms 56608 KB Output is correct
5 Incorrect 369 ms 58156 KB Output isn't correct
6 Halted 0 ms 0 KB -