#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;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
2396 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
2396 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
2396 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
