LeetCode 2264: Largest 3-Same-Digit Number in String

Explanation:

To solve this problem, we can iterate through all substrings of length 3 in the input string and check if each substring consists of only one unique digit. If it does, we compare it with the current maximum good integer found so far and update it if the current substring is larger.

Algorithm:

1. Initialize a variable maxGood as an empty string to store the maximum good integer found.
2. Iterate through all substrings of length 3 in the input string.
3. For each substring, check if it consists of only one unique digit.
4. If it does, compare it with maxGood and update maxGood if the current substring is larger.
5. Return maxGood as the result.

Time Complexity:

• The time complexity of this algorithm is O(n), where n is the length of the input string num.

Space Complexity:

• The space complexity of this algorithm is O(1) as we are using a constant amount of extra space.

:

class Solution {
    public String findGoodNumber(String num) {
        String maxGood = "";
        
        for (int i = 0; i <= num.length() - 3; i++) {
            String current = num.substring(i, i + 3);
            if (current.charAt(0) == current.charAt(1) && current.charAt(1) == current.charAt(2)) {
                if (current.compareTo(maxGood) > 0) {
                    maxGood = current;
                }
            }
        }
        
        return maxGood;
    }
}