#include <bits/stdc++.h>
using namespace std;
const int nx=5e5+5;
int n, vl[nx], q, l, r;
string str;
struct segtree
{
struct node
{
int l, r, sm, ans;
node(): l(0), r(0), sm(0), ans(-1e9){}
node(int x): l(max(0, x)), r(max(0, x)), sm(x), ans(max(0, x)){}
friend node operator+(const node &a, const node &b)
{
if (a.ans==-1e9) return b;
if (b.ans==-1e9) return a;
node res;
res.l=max(a.l, a.sm+b.l);
res.r=max(a.r+b.sm, b.r);
res.sm=a.sm+b.sm;
res.ans=max({a.ans+b.sm, a.sm+b.ans, a.l+b.r});
return res;
}
} d[4*nx];
void build(int l, int r, int i)
{
if (l==r) return d[i]=node(vl[l]), void();
int md=(l+r)/2;
build(l, md, 2*i);
build(md+1, r, 2*i+1);
d[i]=d[2*i]+d[2*i+1];
//cout<<l<<' '<<r<<' '<<d[i].l<<' '<<d[i].r<<' '<<d[i].sm<<' '<<d[i].ans<<'\n';
}
node query(int l, int r, int i, int ql, int qr)
{
if (qr<l||r<ql) return node();
if (ql<=l&&r<=qr) return d[i];
int md=(l+r)/2;
return query(l, md, 2*i, ql, qr)+query(md+1, r, 2*i+1, ql, qr);
}
} s;
int main()
{
cin.tie(NULL)->sync_with_stdio(false);
cin>>n>>str;
str=' '+str;
for (int i=1; i<=n; i++) vl[i]=(str[i]=='T')?1:-1;
s.build(1, n, 1);
cin>>q;
while (q--) cin>>l>>r, cout<<s.query(1, n, 1, l, r).ans<<'\n';
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
33372 KB |
Output is correct |
2 |
Correct |
8 ms |
33392 KB |
Output is correct |
3 |
Correct |
7 ms |
33372 KB |
Output is correct |
4 |
Correct |
7 ms |
33372 KB |
Output is correct |
5 |
Correct |
7 ms |
33372 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
33372 KB |
Output is correct |
2 |
Correct |
8 ms |
33392 KB |
Output is correct |
3 |
Correct |
7 ms |
33372 KB |
Output is correct |
4 |
Correct |
7 ms |
33372 KB |
Output is correct |
5 |
Correct |
7 ms |
33372 KB |
Output is correct |
6 |
Correct |
48 ms |
34416 KB |
Output is correct |
7 |
Correct |
49 ms |
34464 KB |
Output is correct |
8 |
Correct |
48 ms |
34392 KB |
Output is correct |
9 |
Correct |
42 ms |
34384 KB |
Output is correct |
10 |
Correct |
49 ms |
34460 KB |
Output is correct |
11 |
Correct |
49 ms |
34708 KB |
Output is correct |
12 |
Correct |
48 ms |
34612 KB |
Output is correct |
13 |
Correct |
48 ms |
34636 KB |
Output is correct |
14 |
Correct |
55 ms |
34492 KB |
Output is correct |
15 |
Correct |
56 ms |
34636 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
33372 KB |
Output is correct |
2 |
Correct |
8 ms |
33392 KB |
Output is correct |
3 |
Correct |
7 ms |
33372 KB |
Output is correct |
4 |
Correct |
7 ms |
33372 KB |
Output is correct |
5 |
Correct |
7 ms |
33372 KB |
Output is correct |
6 |
Correct |
48 ms |
34416 KB |
Output is correct |
7 |
Correct |
49 ms |
34464 KB |
Output is correct |
8 |
Correct |
48 ms |
34392 KB |
Output is correct |
9 |
Correct |
42 ms |
34384 KB |
Output is correct |
10 |
Correct |
49 ms |
34460 KB |
Output is correct |
11 |
Correct |
49 ms |
34708 KB |
Output is correct |
12 |
Correct |
48 ms |
34612 KB |
Output is correct |
13 |
Correct |
48 ms |
34636 KB |
Output is correct |
14 |
Correct |
55 ms |
34492 KB |
Output is correct |
15 |
Correct |
56 ms |
34636 KB |
Output is correct |
16 |
Correct |
404 ms |
40232 KB |
Output is correct |
17 |
Correct |
359 ms |
39968 KB |
Output is correct |
18 |
Correct |
372 ms |
40280 KB |
Output is correct |
19 |
Correct |
321 ms |
39928 KB |
Output is correct |
20 |
Correct |
413 ms |
39416 KB |
Output is correct |
21 |
Correct |
418 ms |
41132 KB |
Output is correct |
22 |
Correct |
404 ms |
41104 KB |
Output is correct |
23 |
Correct |
400 ms |
41320 KB |
Output is correct |
24 |
Correct |
398 ms |
40956 KB |
Output is correct |
25 |
Correct |
422 ms |
40520 KB |
Output is correct |