【CodeForces】夜深人静写cf

#include <iostream>
#include <algorithm>
#include <string>
#include <map>
using namespace std;
int main() {
  int t;
  cin >> t;
  while (t--) {
    int n, k;
    cin >> n >> k;
    string s;
    cin >> s;
    map<int, int> a, A;
    for (auto c : s) {
      if (c >= 'a' && c <= 'z') a[c - 'a']++;
      else A[c - 'A']++;
    }
    int res = 0, cnt = 0;
    for (int i = 0; i < 26; i++) {
      res += min(a[i], A[i]);
      cnt += abs(a[i] - A[i]) / 2;
    }
    res += min(cnt, k);
    cout << res << endl;
  }
  return 0;
}