Submission #39185216

---

Source Code Expand

#include <bits/stdc++.h>
using namespace std;
int n, k;
string s;
int main() {
  cin.tie(0)->sync_with_stdio(0);
  cin >> n >> k >> s;
  int num = 0, ans = 0;
  for (auto c : s) num += (c == 'X');
  if (num == n) {
    cout << max(0, k - 1) << endl;
    exit(0);
  }
  if (num == 0) {
    cout << max(0, n - 1 - k) << endl;
    exit(0);
  }
  if (num >= k) {
    priority_queue<int, vector<int>, greater<int>> p;
    for (int i = 0, j; i < n; i = j + 1) {
      j = i;
      while (j + 1 < n && s[j + 1] == s[j]) j++;
      if (s[i] == 'X') {
        if (i != 0 && j != n - 1) p.push(j - i + 1);
      } else {
        ans += j - i;
      }
    }
    while (!p.empty() && k >= p.top()) {
      k -= p.top();
      ans += p.top() + 1;
      p.pop();
    }
    ans += k;
    cout << ans << '\n';
  } else {
    k -= num;
    ans = n - 1;
    priority_queue<int> p;
    for (int i = 0, j; i < n; i = j + 1) {
      j = i;
      while (j + 1 < n && s[j + 1] == s[j]) j++;
      if (s[i] == 'Y') {
        if (i != 0 && j != n - 1)
          p.push(j - i + 1);
        else {
          ans -= min(k, j - i + 1);
          k -= min(k, j - i + 1);
        }
      }
    }
    while (k) {
      ans -= min(k, p.top()) + 1;
      k -= min(k, p.top());
      p.pop();
    }
    cout << ans << '\n';
  }
  return 0;
}

Submission Info

Judge Result