Peli

#include <iostream>

bool have[3];

int main() {
  std::ios::sync_with_stdio(false);
  std::cin.tie(nullptr);

  uint32_t n, k;
  std::cin >> n >> k;
  std::string kirj;
  std::cin >> kirj;

  if (k < 3) {
    std::cout << "0\n";
    return 0;
  }
  uint32_t res = 0;
  if (k == 3) {
    for (auto c : kirj) {
      if (have[c - 'A'])
        continue;
      have[c - 'A'] = true;
      if (have[0] && have[1] && have[2]) {
        ++res;
        have[0] = have[1] = have[2] = false;
      }
    }
    std::cout << res << '\n';
    return 0;
  } else {
    return 1;
  }
}

Test 1

Group: 1, 2, 3

Verdict: ACCEPTED

Test 2

Group: 2, 3

Verdict: RUNTIME ERROR

Test 3

Group: 3

Verdict: RUNTIME ERROR

Test 4

Group: 1, 2, 3

Verdict: ACCEPTED

Test 5

Group: 1, 2, 3

Verdict: ACCEPTED