// 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], pos[N * 4];
int comb(int i, int j) {
return a[i] >= a[j] ? i : j;
}
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]);
pos[id] = comb(pos[id*2], pos[id*2+1]);
}
else {
sgt[id] = a[lb];
pos[id] = 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 findpos(int id, int lb, int rb, int l, int r) {
if (l <= lb && rb <= r) return pos[id];
if (rb < l || lb > r) return 0;
int mb = (lb + rb) >> 1;
return comb(findpos(id*2, lb, mb, l, r), findpos(id*2+1, mb+1, rb, l, r));
}
int solve(int l, int r) {
if ((r-l+1) < 3) return 0;
int pos_max = findpos(1, 1, n, l+1, r-1);
int ans = max(solve(l, pos_max), solve(pos_max, r));
if (r - pos_max < pos_max - l) {
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];
build(1, 1, n);
cin >> q;
foru(i, 1, q) {
int l, r;
cin >> l >> r;
cout << solve(l, r) << "\n";
}
// cout << solve(1, n);
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
4444 KB |
Output is correct |
2 |
Incorrect |
2 ms |
4444 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
4444 KB |
Output is correct |
2 |
Incorrect |
2 ms |
4444 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
267 ms |
8808 KB |
Output is correct |
2 |
Correct |
132 ms |
24400 KB |
Output is correct |
3 |
Correct |
128 ms |
24248 KB |
Output is correct |
4 |
Correct |
271 ms |
8804 KB |
Output is correct |
5 |
Correct |
285 ms |
8784 KB |
Output is correct |
6 |
Correct |
243 ms |
8808 KB |
Output is correct |
7 |
Correct |
238 ms |
8888 KB |
Output is correct |
8 |
Correct |
233 ms |
8804 KB |
Output is correct |
9 |
Correct |
244 ms |
8804 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
4444 KB |
Output is correct |
2 |
Incorrect |
2 ms |
4444 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |