제출 #237204

#제출 시각아이디문제언어결과실행 시간메모리
237204manh92033단 점프 (JOI19_jumps)C++17
100 / 100
1483 ms108280 KiB
#include<bits/stdc++.h>

using namespace std;

#define ll long long
const int N = 5e5 + 5;

ll n, a[N];
int q, L[N], R[N];
vector<int> queRy[N];
vector<int> add[N];
ll ans[N];

struct node {
	ll D, C, lz;
} st[4 * N];

void build(int id, int l, int r) {
	if (l == r) {
		st[id].C = a[l];
		return;
	}
	int mid = (l + r) >> 1;
	build(id << 1, l, mid);
	build(id << 1 | 1, mid + 1, r);
	st[id].D = max(st[id << 1].D, st[id << 1 | 1].D);
	st[id].C = max(st[id << 1].C, st[id << 1 | 1].C);
}

void pushDown(int id, int l, int r) {
	if (st[id].lz != 0) {
		st[id].D = max(st[id].D, st[id].C + st[id].lz);
		if (l < r) {
			st[id << 1].lz = max(st[id << 1].lz, st[id].lz);
			st[id << 1 | 1].lz = max(st[id << 1 | 1].lz, st[id].lz); 
		}
		st[id].lz = 0;
	}
}
void update(int id, int l, int r, int i, int j, int x) {
	pushDown(id, l, r);
	if (l > j || r < i || i > j) {
		return;
	}
	if (l >= i && r <= j) {
		st[id].lz = x;
		pushDown(id, l, r);
		return;
	}
	int mid = (l + r) >> 1;
	update(id << 1, l, mid, i, j, x);
	update(id << 1 | 1, mid + 1, r, i, j, x);
	st[id].D = max(st[id << 1].D, st[id << 1 | 1].D);
}
ll get(int id, int l, int r, int i, int j) {
	pushDown(id, l, r);
	if (l > j || r < i || i > j) {
		return 0;
	}
	if (l >= i && r <= j) {
		return st[id].D;
	}
	int mid = (l + r) >> 1;
	return max(get(id << 1, l, mid, i, j), get(id << 1 | 1, mid + 1, r, i, j));
}

int main() {
	ios_base::sync_with_stdio(0); cin.tie(0);
	
	cin >> n;
	for (int i = 1; i <= n; i++) cin >> a[i];
	cin >> q;
	for (int i = 1; i <= q; i++) {
		cin >> L[i] >> R[i];
		queRy[L[i]].push_back(i);
	}
	
	vector<int> s;
	for (int i = 1; i <= n; i++) {
		while (s.size() > 0 && a[s.back()] < a[i]) {
			s.pop_back();
		}
		if (s.size() > 0) {
			add[s.back()].push_back(i);
		}
		s.push_back(i);
	}
	
	s.clear();
	for (int i = n; i >= 1; i--) {
		while (s.size() > 0 && a[s.back()] < a[i]) {
			s.pop_back();
		}
		if (s.size() > 0) {
			add[i].push_back(s.back());
		}
		s.push_back(i);
	}
	
	build(1, 1, n);
	for (int i = n; i >= 1; i--) {
		for (int j : add[i]) {
			update(1, 1, n, 2 * j - i, n, a[i] + a[j]);
		}
		for (int j : queRy[i]) {
			ans[j] = get(1, 1, n, L[j], R[j]);
		}
	}
	
	for (int i = 1; i <= q; i++) {
		cout << ans[i] << "\n";
	}
}
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