oj.uz

Submission #588873

# Submission time Handle Problem Language Result Execution time Memory
588873 2022-07-04T06:46:39 Z Arnch Event Hopping (BOI22_events) C++17
30 / 100
 449 ms 59376 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, 0, 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], 2 * n, 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 + 2 <<endl;
			continue;
		}
		cout<<"impossible" <<endl;
	}

    return 0;
}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 31588 KB Output is correct
2 Correct 361 ms 56616 KB Output is correct
3 Correct 362 ms 56520 KB Output is correct
4 Correct 386 ms 56580 KB Output is correct
5 Correct 407 ms 56588 KB Output is correct
6 Correct 380 ms 56592 KB Output is correct
7 Correct 384 ms 56656 KB Output is correct
8 Correct 408 ms 58708 KB Output is correct
9 Correct 359 ms 59376 KB Output is correct
10 Correct 402 ms 59192 KB Output is correct
11 Correct 399 ms 58584 KB Output is correct
12 Correct 289 ms 57716 KB Output is correct

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 31640 KB Output is correct
2 Correct 13 ms 31584 KB Output is correct
3 Correct 14 ms 31888 KB Output is correct
4 Correct 16 ms 31828 KB Output is correct
5 Correct 16 ms 31828 KB Output is correct
6 Incorrect 15 ms 31900 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 31640 KB Output is correct
2 Correct 13 ms 31584 KB Output is correct
3 Correct 14 ms 31888 KB Output is correct
4 Correct 16 ms 31828 KB Output is correct
5 Correct 16 ms 31828 KB Output is correct
6 Incorrect 15 ms 31900 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 31640 KB Output is correct
2 Correct 13 ms 31584 KB Output is correct
3 Correct 14 ms 31888 KB Output is correct
4 Correct 16 ms 31828 KB Output is correct
5 Correct 16 ms 31828 KB Output is correct
6 Incorrect 15 ms 31900 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #5
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 365 ms 56584 KB Output is correct
2 Correct 399 ms 56604 KB Output is correct
3 Correct 388 ms 56580 KB Output is correct
4 Correct 364 ms 57128 KB Output is correct
5 Correct 415 ms 57000 KB Output is correct
6 Correct 406 ms 56720 KB Output is correct
7 Correct 449 ms 56824 KB Output is correct
8 Correct 370 ms 56812 KB Output is correct
9 Correct 187 ms 55972 KB Output is correct
10 Correct 353 ms 56492 KB Output is correct
11 Correct 408 ms 56232 KB Output is correct
12 Correct 364 ms 56512 KB Output is correct

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 31588 KB Output is correct
2 Correct 361 ms 56616 KB Output is correct
3 Correct 362 ms 56520 KB Output is correct
4 Correct 386 ms 56580 KB Output is correct
5 Correct 407 ms 56588 KB Output is correct
6 Correct 380 ms 56592 KB Output is correct
7 Correct 384 ms 56656 KB Output is correct
8 Correct 408 ms 58708 KB Output is correct
9 Correct 359 ms 59376 KB Output is correct
10 Correct 402 ms 59192 KB Output is correct
11 Correct 399 ms 58584 KB Output is correct
12 Correct 289 ms 57716 KB Output is correct
13 Correct 13 ms 31640 KB Output is correct
14 Correct 13 ms 31584 KB Output is correct
15 Correct 14 ms 31888 KB Output is correct
16 Correct 16 ms 31828 KB Output is correct
17 Correct 16 ms 31828 KB Output is correct
18 Incorrect 15 ms 31900 KB Output isn't correct
19 Halted 0 ms 0 KB -