#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 2e5 + 5;
int a[4*N], nxt[3*N][2];
int idx[4*N][2], vis[2*N];
vector<int> pos;
ll solve(int n, int i) {
int ptr[2] = {i+n, i+n};
ll val = 0;
for (int j = i; j < i+n; ++j)
val += min((ptr[a[j]] = nxt[ptr[a[j]]][a[j]] + 1) - n - i - 1, j - i);
return val;
}
int main() {
ios_base::sync_with_stdio(false); cin.tie(0);
int n; cin >> n;
string s; cin >> s;
for (int i = 0; i < 2*n; i++)
a[i] = a[i+2*n] = s[i] == 'B';
nxt[3*n][0] = nxt[3*n][1] = 3*n;
for (int i = 3*n-1; i >= 0; i--) {
nxt[i][0] = nxt[i+1][0], nxt[i][1] = nxt[i+1][1];
nxt[i][a[i]^1] = i;
}
idx[0][a[0]] = 1, idx[0][a[0]^1] = 0;
for (int i = 1; i < 4*n; i++) {
idx[i][0] = idx[i-1][0], idx[i][1] = idx[i-1][1];
idx[i][a[i]]++;
}
for (int i = 0; i < n; i++)
vis[idx[nxt[i+n][a[i]]][a[i]^1] - idx[i][a[i]]] = i+1;
for (int i = n/2; i < n; i++) if (vis[i])
pos.push_back(vis[i] - 1);
ll ans = solve(n, 0);
int lo = 0, hi = pos.size() - 1;
while (lo <= hi) {
int mi = (lo + hi) / 2;
ll x1 = solve(n, pos[mi]);
ans = max(ans, x1);
if (lo == hi)
break;
if (x1 < solve(n, pos[mi+1]))
lo = mi + 1;
else
hi = mi - 1;
}
cout << ans << "\n";
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
384 KB |
Output is correct |
| 2 |
Correct |
0 ms |
384 KB |
Output is correct |
| 3 |
Correct |
1 ms |
384 KB |
Output is correct |
| 4 |
Correct |
0 ms |
384 KB |
Output is correct |
| 5 |
Correct |
1 ms |
384 KB |
Output is correct |
| 6 |
Correct |
0 ms |
384 KB |
Output is correct |
| 7 |
Correct |
1 ms |
384 KB |
Output is correct |
| 8 |
Correct |
1 ms |
384 KB |
Output is correct |
| 9 |
Correct |
1 ms |
384 KB |
Output is correct |
| 10 |
Correct |
1 ms |
384 KB |
Output is correct |
| 11 |
Correct |
1 ms |
384 KB |
Output is correct |
| 12 |
Correct |
0 ms |
384 KB |
Output is correct |
| 13 |
Correct |
1 ms |
384 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
384 KB |
Output is correct |
| 2 |
Correct |
0 ms |
384 KB |
Output is correct |
| 3 |
Correct |
1 ms |
384 KB |
Output is correct |
| 4 |
Correct |
0 ms |
384 KB |
Output is correct |
| 5 |
Correct |
1 ms |
384 KB |
Output is correct |
| 6 |
Correct |
0 ms |
384 KB |
Output is correct |
| 7 |
Correct |
1 ms |
384 KB |
Output is correct |
| 8 |
Correct |
1 ms |
384 KB |
Output is correct |
| 9 |
Correct |
1 ms |
384 KB |
Output is correct |
| 10 |
Correct |
1 ms |
384 KB |
Output is correct |
| 11 |
Correct |
1 ms |
384 KB |
Output is correct |
| 12 |
Correct |
0 ms |
384 KB |
Output is correct |
| 13 |
Correct |
1 ms |
384 KB |
Output is correct |
| 14 |
Correct |
1 ms |
384 KB |
Output is correct |
| 15 |
Correct |
1 ms |
396 KB |
Output is correct |
| 16 |
Correct |
0 ms |
384 KB |
Output is correct |
| 17 |
Correct |
1 ms |
396 KB |
Output is correct |
| 18 |
Correct |
1 ms |
384 KB |
Output is correct |
| 19 |
Correct |
0 ms |
384 KB |
Output is correct |
| 20 |
Correct |
1 ms |
384 KB |
Output is correct |
| 21 |
Incorrect |
1 ms |
384 KB |
Output isn't correct |
| 22 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
384 KB |
Output is correct |
| 2 |
Correct |
0 ms |
384 KB |
Output is correct |
| 3 |
Correct |
1 ms |
384 KB |
Output is correct |
| 4 |
Correct |
0 ms |
384 KB |
Output is correct |
| 5 |
Correct |
1 ms |
384 KB |
Output is correct |
| 6 |
Correct |
0 ms |
384 KB |
Output is correct |
| 7 |
Correct |
1 ms |
384 KB |
Output is correct |
| 8 |
Correct |
1 ms |
384 KB |
Output is correct |
| 9 |
Correct |
1 ms |
384 KB |
Output is correct |
| 10 |
Correct |
1 ms |
384 KB |
Output is correct |
| 11 |
Correct |
1 ms |
384 KB |
Output is correct |
| 12 |
Correct |
0 ms |
384 KB |
Output is correct |
| 13 |
Correct |
1 ms |
384 KB |
Output is correct |
| 14 |
Correct |
1 ms |
384 KB |
Output is correct |
| 15 |
Correct |
1 ms |
396 KB |
Output is correct |
| 16 |
Correct |
0 ms |
384 KB |
Output is correct |
| 17 |
Correct |
1 ms |
396 KB |
Output is correct |
| 18 |
Correct |
1 ms |
384 KB |
Output is correct |
| 19 |
Correct |
0 ms |
384 KB |
Output is correct |
| 20 |
Correct |
1 ms |
384 KB |
Output is correct |
| 21 |
Incorrect |
1 ms |
384 KB |
Output isn't correct |
| 22 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
384 KB |
Output is correct |
| 2 |
Correct |
0 ms |
384 KB |
Output is correct |
| 3 |
Correct |
1 ms |
384 KB |
Output is correct |
| 4 |
Correct |
0 ms |
384 KB |
Output is correct |
| 5 |
Correct |
1 ms |
384 KB |
Output is correct |
| 6 |
Correct |
0 ms |
384 KB |
Output is correct |
| 7 |
Correct |
1 ms |
384 KB |
Output is correct |
| 8 |
Correct |
1 ms |
384 KB |
Output is correct |
| 9 |
Correct |
1 ms |
384 KB |
Output is correct |
| 10 |
Correct |
1 ms |
384 KB |
Output is correct |
| 11 |
Correct |
1 ms |
384 KB |
Output is correct |
| 12 |
Correct |
0 ms |
384 KB |
Output is correct |
| 13 |
Correct |
1 ms |
384 KB |
Output is correct |
| 14 |
Correct |
1 ms |
384 KB |
Output is correct |
| 15 |
Correct |
1 ms |
396 KB |
Output is correct |
| 16 |
Correct |
0 ms |
384 KB |
Output is correct |
| 17 |
Correct |
1 ms |
396 KB |
Output is correct |
| 18 |
Correct |
1 ms |
384 KB |
Output is correct |
| 19 |
Correct |
0 ms |
384 KB |
Output is correct |
| 20 |
Correct |
1 ms |
384 KB |
Output is correct |
| 21 |
Incorrect |
1 ms |
384 KB |
Output isn't correct |
| 22 |
Halted |
0 ms |
0 KB |
- |
