#include <bits/stdc++.h>
#define FOR(i, x, y) for (int i = x; i < y; i++)
typedef long long ll;
using namespace std;
struct Node {
int l_max, r_max, tot, ans;
Node operator+(Node b) {
Node ret;
ret.l_max = max(l_max, b.l_max + tot);
ret.r_max = max(r_max + b.tot, b.r_max);
ret.tot = tot + b.tot;
ret.ans = max(max(ans + b.tot, b.ans + tot), l_max + b.r_max);
return ret;
}
};
Node segtree[2000001];
char s[500001];
int n;
void build(int node = 1, int l = 1, int r = n) {
if (l == r) {
if (s[l] == 'T') segtree[node] = {1, 1, 1, 1};
else segtree[node] = {0, 0, -1, 0};
} else {
int mid = (l + r) / 2;
build(node * 2, l, mid);
build(node * 2 + 1, mid + 1, r);
segtree[node] = segtree[node * 2] + segtree[node * 2 + 1];
}
}
Node query(int a, int b, int node = 1, int l = 1, int r = n) {
if (l > b || r < a) return {0, 0, 0, 0};
if (l >= a && r <= b) return segtree[node];
int mid = (l + r) / 2;
return query(a, b, node * 2, l, mid) + query(a, b, node * 2 + 1, mid + 1, r);
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> n;
FOR(i, 1, n + 1) cin >> s[i];
build();
int q;
cin >> q;
while (q--) {
int a, b;
cin >> a >> b;
cout << query(a, b).ans << '\n';
}
return 0;
}
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
1 ms |
348 KB |
Output is correct |
| 2 |
Correct |
1 ms |
348 KB |
Output is correct |
| 3 |
Correct |
1 ms |
348 KB |
Output is correct |
| 4 |
Correct |
2 ms |
560 KB |
Output is correct |
| 5 |
Correct |
2 ms |
348 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
1 ms |
348 KB |
Output is correct |
| 2 |
Correct |
1 ms |
348 KB |
Output is correct |
| 3 |
Correct |
1 ms |
348 KB |
Output is correct |
| 4 |
Correct |
2 ms |
560 KB |
Output is correct |
| 5 |
Correct |
2 ms |
348 KB |
Output is correct |
| 6 |
Correct |
36 ms |
5804 KB |
Output is correct |
| 7 |
Correct |
35 ms |
5664 KB |
Output is correct |
| 8 |
Correct |
42 ms |
5596 KB |
Output is correct |
| 9 |
Correct |
30 ms |
5724 KB |
Output is correct |
| 10 |
Correct |
35 ms |
5604 KB |
Output is correct |
| 11 |
Correct |
45 ms |
5980 KB |
Output is correct |
| 12 |
Correct |
45 ms |
5720 KB |
Output is correct |
| 13 |
Correct |
35 ms |
5724 KB |
Output is correct |
| 14 |
Correct |
38 ms |
5652 KB |
Output is correct |
| 15 |
Correct |
38 ms |
5716 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
1 ms |
348 KB |
Output is correct |
| 2 |
Correct |
1 ms |
348 KB |
Output is correct |
| 3 |
Correct |
1 ms |
348 KB |
Output is correct |
| 4 |
Correct |
2 ms |
560 KB |
Output is correct |
| 5 |
Correct |
2 ms |
348 KB |
Output is correct |
| 6 |
Correct |
36 ms |
5804 KB |
Output is correct |
| 7 |
Correct |
35 ms |
5664 KB |
Output is correct |
| 8 |
Correct |
42 ms |
5596 KB |
Output is correct |
| 9 |
Correct |
30 ms |
5724 KB |
Output is correct |
| 10 |
Correct |
35 ms |
5604 KB |
Output is correct |
| 11 |
Correct |
45 ms |
5980 KB |
Output is correct |
| 12 |
Correct |
45 ms |
5720 KB |
Output is correct |
| 13 |
Correct |
35 ms |
5724 KB |
Output is correct |
| 14 |
Correct |
38 ms |
5652 KB |
Output is correct |
| 15 |
Correct |
38 ms |
5716 KB |
Output is correct |
| 16 |
Correct |
335 ms |
26968 KB |
Output is correct |
| 17 |
Correct |
280 ms |
26448 KB |
Output is correct |
| 18 |
Correct |
308 ms |
26708 KB |
Output is correct |
| 19 |
Correct |
251 ms |
26192 KB |
Output is correct |
| 20 |
Correct |
320 ms |
25936 KB |
Output is correct |
| 21 |
Correct |
328 ms |
27752 KB |
Output is correct |
| 22 |
Correct |
324 ms |
27732 KB |
Output is correct |
| 23 |
Correct |
342 ms |
27988 KB |
Output is correct |
| 24 |
Correct |
332 ms |
27740 KB |
Output is correct |
| 25 |
Correct |
341 ms |
26976 KB |
Output is correct |
