#include <bits/stdc++.h>
#pragma GCC optimize("O3")
#define endl '\n'
using namespace std;
const int maxn = 5e5 + 3;
int n, q;
string s;
void read()
{
cin >> n >> s >> q;
}
struct node
{
int to_delete, sum, min_suffix;
node() {}
node(int to_delete, int sum, int min_suffix)
{
this->to_delete = to_delete;
this->sum = sum;
this->min_suffix = min_suffix;
}
};
int get_min(vector <pair <int, int> > &v)
{
int ans = 0;
for (auto i: v)
ans = min(ans, i.second);
return ans;
}
vector <node> tr[maxn * 4];
void build(int v, int l, int r)
{
int len = r - l + 1;
tr[v].resize(len + 1);
vector <pair <int, int> > st;
st.push_back({r + 1, 0});
int balance = 0;
for (int i = r; i >= l; i--)
{
if (s[i-1] == 'C')
balance++;
else
balance--;
if (balance < st.back().second)
st.push_back({i, balance});
}
reverse (st.begin(), st.end());
vector <int> f(len + 1, -1);
balance = 0;
for (int i = l; i <= r; i++)
{
if (s[i-1] == 'C')
balance++;
else
balance--;
for (int j = -balance-1; j >= 0; j--)
if (f[j] == -1)
f[j] = i;
}
int curr_del = 0;
for (int i = len; i >= 0; i--)
{
if (f[i] != -1 && f[i] != f[i+1])
{
for (auto &j: st)
if (j.first <= f[i])
j.second++;
curr_del++;
balance++;
}
tr[v][i] = node(curr_del, balance, get_min(st));
}
if (l == r)
return;
int mid = (l + r) / 2;
build(v * 2, l, mid);
build(v * 2 + 1, mid + 1, r);
}
vector <int> curr;
void get(int v, int l, int r, int ll, int rr)
{
if (l > rr || r < ll)
return;
if (l >= ll && r <= rr)
{
curr.push_back(v);
return;
}
int mid = (l + r) / 2;
get (v * 2, l, mid, ll, rr);
get (v * 2 + 1, mid + 1, r, ll, rr);
}
void solve()
{
build(1, 1, n);
while (q--)
{
int l, r;
cin >> l >> r;
curr.clear();
get(1, 1, n, l, r);
int ans = 0;
int balance = 0;
vector <pair <int, int> > v;
for (auto i: curr)
{
auto temp = tr[i][min((int)tr[i].size(), balance)];
ans += temp.to_delete;
balance += temp.sum;
v.push_back({temp.sum, temp.min_suffix});
}
balance = 0;
int to_add = 0;
for (int i = (int)v.size() - 1; i >= 0; i--)
{
to_add = min(to_add, balance + v[i].second);
balance += v[i].first;
}
cout << ans - to_add << endl;
}
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
read();
solve();
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
37 ms |
47724 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
37 ms |
47724 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
37 ms |
47724 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |