Submission #882278

#	Time	Username	Problem	Language	Result	Execution time	Memory
882278		OAleksa	Election (BOI18_election)	C++14	100 / 100	498 ms	44636 KiB

election

#include<bits/stdc++.h>
using namespace std;
#define f first
#define s second
#define int long long
const int maxn = 5e5 + 69;
struct Node {
	int p, s, ans, sm;
} st[4 * maxn];
int n, q;
string s;
Node combine(Node a, Node b) {
	Node ret;
	ret.p = max(a.p, a.sm + b.p);
	ret.s = max(b.s, b.sm + a.s);
	ret.sm = a.sm + b.sm;
	ret.ans = max({a.sm + b.ans, b.sm + a.ans, a.p + b.s});
	return ret;
}
void build(int v, int tl, int tr) {
	if (tl == tr) {
		if (s[tl - 1] == 'T')
			st[v].p = st[v].s = st[v].sm = st[v].ans = 1;
		else {
			st[v].p = st[v].s = st[v].ans = 0;
			st[v].sm = -1;
		}
	}
	else {
		int mid = (tl + tr) / 2;
		build(v * 2, tl, mid);
		build(v * 2 + 1, mid + 1, tr);
		st[v] = combine(st[v * 2], st[v * 2 + 1]);
	}
}
Node qry(int v, int tl, int tr, int l, int r) {
	if (tl > r || tr < l)
		return {0, 0, 0, 0};
	else if (tl >= l && tr <= r)
		return st[v];
	else {
		int mid = (tl + tr) / 2;
		return combine(qry(v * 2, tl, mid, l, r), qry(v * 2 + 1, mid + 1, tr, l, r));
	}
}
signed main() {
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
  int tt = 1;
  //cin >> tt;
  while (tt--) {
   	cin >> n >> s >> q;
   	build(1, 1, n);
   	for (int i = 1;i <= q;i++) {
   		int l, r;
   		cin >> l >> r;
   		cout << qry(1, 1, n, l, r).ans << '\n';
   	}
	}
	return 0;
}

• Subtask 1: 28 / 28
• Subtask 2: 54 / 54
• Subtask 3: 18 / 18