content: package codingquestions.leetcode;
  
  /*
  2264. Largest 3-Same-Digit Number in String
  Solved
  Easy
  Topics
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  Hint
  You are given a string num representing a large integer. An integer is good if it meets the following conditions:
  
  It is a substring of num with length 3.
  It consists of only one unique digit.
  Return the maximum good integer as a string or an empty string "" if no such integer exists.
  
  Note:
  
  A substring is a contiguous sequence of characters within a string.
  There may be leading zeroes in num or a good integer.
   
  
  Example 1:
  
  Input: num = "6777133339"
  Output: "777"
  Explanation: There are two distinct good integers: "777" and "333".
  "777" is the largest, so we return "777".
  Example 2:
  
  Input: num = "2300019"
  Output: "000"
  Explanation: "000" is the only good integer.
  Example 3:
  
  Input: num = "42352338"
  Output: ""
  Explanation: No substring of length 3 consists of only one unique digit. Therefore, there are no good integers.
   
  
  Constraints:
  
  3 <= num.length <= 1000
  num only consists of digits.
  */
  class Largest3SameDigitNumberInString {
      public String largestGoodInteger(String num) {
          String res = "";
          for(int i = 2; i < num.length(); i++){
              String cur = num.substring(i - 2, i + 1);
              if(cur.charAt(0) == cur.charAt(1) && cur.charAt(1) == cur.charAt(2)){
                  if(res == "" || res.compareTo(cur) < 0)
                      res = cur;
              }
          }
          return res;
      }
  }
  