Submission #950426

#	Time	Username	Problem	Language	Result	Execution time	Memory
950426		vjudge1	Triple Jump (JOI19_jumps)	C++17	19 / 100	455 ms	152716 KiB

jumps

#include<bits/stdc++.h>

using namespace std;

const int N = (int)5e5+7;
const int M = (int)2e5+7;
const int inf = (int)1e9+7;

int n, q, a[N];
int dp[5003][5003], mx[5003][5003];
pair<int, int> suf[N];
int l[N], r[N];
int ans;

void calc(int i, int j) {
	if(j+(j-i)<=n) {
		ans = max(ans, a[i]+a[j]+suf[j+(j-i)].first);
	}
}

void solve3() {
	cin >> q >> q >> q;
	for(int i = n; i >= 1; --i) {
		suf[i] = max(suf[i+1], {a[i], i});
	}                                  	
	stack<int> st;
	for(int i = 1; i <= n; ++i) {
		l[i] = i;
		while(!st.empty() && a[st.top()]<a[i]) {
		    l[i]=l[st.top()];
			st.pop();
		}
		st.push(i);
	}
	while(!st.empty()) {
		continue;
	}
	for(int i = n; i >= 1; --i) {
		r[i] = i;
		while(!st.empty() && a[st.top()]<a[i]) {
			r[i] = r[st.top()];
			st.pop();
		}
	}
	for(int i = 1; i < n; ++i) {
		int j = r[i]+1;
		if(j <= n) {
			calc(i, j);
		}		
	}
	for(int i = 2; i < n; ++i) {
		int j = l[i]-1;
		if(j >= 1) {
			calc(j, i);
		}
	}
	cout << ans;
}

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cin >> n;
	for(int i = 1; i <= n; ++i) {
		cin >> a[i];
	} 
	if(n>5000) {
		solve3();
		return 0;
	}
	for(int i = 1; i <= n; ++i) {
		for(int j = i; j <= n; ++j) {
			mx[i][j] = max(mx[i][j-1], a[j]);
		}
	}
	for(int len = 3; len <= n; ++len) {
		for(int i = 1; i <= n-len+1; ++i) {
			int j = i+len-1;
			dp[i][j]=max(dp[i+1][j], dp[i][j-1]);
			int cur = a[i]+a[j];
			int m = (i+j)/2;
			cur += mx[i+1][m];
			dp[i][j] = max(dp[i][j], cur);
		}
	}
	cin >> q;
	while(q--) {
		int l, r;
		cin >> l >> r;
		cout << dp[l][r] << "\n";
	}
    return 0;
}

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