1957. Delete Characters to Make Fancy String

 JAVA

• class Solution {
      public String makeFancyString(String s) {
          StringBuffer sb = new StringBuffer();
          int length = s.length();
          char prev = ' ';
          int count = 1;
          for (int i = 0; i < length; i++) {
              char curr = s.charAt(i);
              if (curr == prev)
                  count++;
              else {
                  count = 1;
                  prev = curr;
              }
              if (count < 3)
                  sb.append(curr);
          }
          return sb.toString();
      }
  }
  
  ############
  
  class Solution {
      public String makeFancyString(String s) {
          StringBuilder ans = new StringBuilder();
          for (char c : s.toCharArray()) {
              int n = ans.length();
              if (n > 1 && ans.charAt(n - 1) == c && ans.charAt(n - 2) == c) {
                  continue;
              }
              ans.append(c);
          }
          return ans.toString();
      }
  }

C++

class Solution {
public:
    string makeFancyString(string s) {
        int i = 0, j = 0, N = s.size();
        while (i < N) {
            int start = i;
            while (i < N && s[i] == s[start]) {
                if (i - start < 2) s[j++] = s[i];
                ++i;
            }
        }
        s.resize(j);
        return s;
    }
};