bai2.cpp

#include <bits/stdc++.h>
using namespace std;

int main() {
  string s; char c;
  cout << "Nhap s: "; getline(cin, s);
  cout << "Nhap c: "; cin >> c;
  int cnt = 0;
  for (int i = 0; i < s.size(); i++) {
    if (s[i] == c) cnt++;
  }
  cout << "So ky tu c trong xau s: " << cnt << '\n';
}