Submission #859239

#	Time	Username	Problem	Language	Result	Execution time	Memory
859239		mgl_diamond	Triple Jump (JOI19_jumps)	C++17	0 / 100	4049 ms	7256 KiB

jumps

// Source: https://usaco.guide/general/io

#include <bits/stdc++.h>
using namespace std;


#define foru(i, l, r) for(int i=(l); i<=(r); ++i)
#define ford(i, l, r) for(int i=(l); i>=(r); --i)

const int N = 5e5+5;
const int BIG = 2e9;
int n, q, a[N];
int sgt[N * 4];

void build(int id, int lb, int rb) {
	if (lb ^ rb) {
		int mb = (lb + rb) >> 1;
		build(id*2, lb, mb);
		build(id*2+1, mb+1, rb);
		sgt[id] = max(sgt[id*2], sgt[id*2+1]);
	}
	else {
		sgt[id] = a[lb];
	}
}

int query(int id, int lb, int rb, int l, int r) {
	if (l <= lb && rb <= r) return sgt[id];
	if (rb < l || lb > r) return -BIG;
	int mb = (lb + rb) >> 1;
	return max(query(id*2, lb, mb, l, r), query(id*2+1, mb+1, rb, l, r));
}

int solve(int l, int r) {
	if ((r-l+1) < 3) return 0;

	int pos_max = -1;
	for(int i=l+1 ; i<=r-1; ++i) {
		if (pos_max == -1 || a[pos_max] < a[i])
			pos_max = i;
	}

	int ans = max(solve(l, pos_max), solve(pos_max, r));
	
	if (r - pos_max < l - pos_max) {
		for(int d = 1; d <= r - pos_max; ++d) {
			int k = pos_max+d;
			ans = max(ans, a[k] + a[pos_max] + query(1, 1, n, pos_max-d, pos_max-1));
		}
	}
	else {
		for(int d = 1; d <= pos_max - l; ++d) {
			int k = pos_max - d;
			ans = max(ans, a[k] + a[pos_max] + query(1, 1, n, pos_max+d, r));
		}
	}

	// cout << l << " " << r << " " << ans << "\n";
	return ans;
}

int main() {
	cin >> n;
	foru(i, 1, n) cin >> a[i];
	cin >> q;
	foru(i, 1, q) {
		int l, r;
		cin >> l >> r;
	}
	build(1, 1, n);
	// cout << a[1] + a[2] + query(1, 1, n, 3, n) << "\n";
	// cout << query(1, 1, n, 3, n) << "\n";
	// cout << a[1] << " " << a[2] << "\n";
	cout << solve(1, n);
	return 0;
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 14
• Subtask 3: 0 / 27
• Subtask 4: 0 / 54