제출 #345552

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
345552		darkxeon	Hedgehog Daniyar and Algorithms (IZhO19_sortbooks)	C++17	100 / 100	1102 ms	83444 KiB

sortbooks

#include <bits/stdc++.h>
#define sz(x) (long long)(x).size()
 
using namespace std;
 
//mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
 
const int N = 1e5 + 5, M = 1e6 + 7, SM = 1e3 + 5, logN = 20;
const long long MOD = 1e9 + 7, INF = 1e18 + 9;
const int dx[] = {1, 0, 0, -1, -1, 1, -1, 1};
const int dy[] = {0, 1, -1, 0, -1, 1, 1, -1};
 
void debug() {
	cerr << "\n";
}
template<typename Head, typename... Tail>
void debug(Head a, Tail... b) {
	cerr << a << " ";
	debug(b...);
}

struct Query {
	long long l, k, i;
};

vector<Query> q[M];

long long n, m, a[M], t[M], ans[M];

void update(long long i, long long x) {
	i = n - i + 1;
	for(; i <= n; i += i & -i) {
		t[i] = max(t[i], x);
	}
}

long long getMax(long long l) {
	l = n - l + 1;
	long long res = 0;
	for(; l >= 1; l -= l & -l) {
		res = max(res, t[l]);
	}
	return res;
}

int main() {
	//freopen(".in", "r", stdin);
	//freopen(".out", "w", stdout);
	ios_base::sync_with_stdio(false);
	cin.tie(0), cout.tie(0);
	
	cin >> n >> m;
	
	for(long long i = 1; i <= n; i++) {
		cin >> a[i];
	}
		
	for(long long i = 1; i <= m; i++) {
		long long l, r, k; cin >> l >> r >> k;
		q[r].push_back({l, k, i});
	}	
	
	/* Main observation: 
	 * We can't re-arrange given segment if and only if, 
	 * there is a pair of indices i and j, which are
	 * i < j, a[i] > a[j] and a[i] + a[j] > k
	 * 
	 * 
	 * @seduneon
	 */
	
	stack<long long> s;
	for(long long r = 1; r <= n; r++) {
		// Stack Trick to find first greater value on the left in O(n)
		while(!s.empty() && a[r] >= a[s.top()]) {
			s.pop();
		}
		if(!s.empty()) {
			// We should keep following sum on left position
			update(s.top(), a[r] + a[s.top()]);
		}
		s.push(r);
		for(auto [l, k, i] : q[r]) {
			ans[i] = (getMax(l) <= k);
		}
	}
	
	for(long long i = 1; i <= m; i++) {
		cout << ans[i] << "\n";
	}
	
	cout << endl;
	return 0;
}

• Subtask 1: 8 / 8
• Subtask 2: 9 / 9
• Subtask 3: 13 / 13
• Subtask 4: 17 / 17
• Subtask 5: 30 / 30
• Subtask 6: 23 / 23