Longest Happy String

A string s is called happy if it satisfies the following conditions:

• s only contains the letters 'a', 'b', and 'c'.

• s does not contain any of "aaa", "bbb", or "ccc" as a substring.

• s contains at most a occurrences of the letter 'a'.

• s contains at most b occurrences of the letter 'b'.

• s contains at most c occurrences of the letter 'c'.

Given three integers a, b, and c, return the longest possible happy string. If there are multiple longest happy strings, return any of them. If there is no such string, return the empty string "".

A substring is a contiguous sequence of characters within a string.

LeetCode Problem - 1405

class Solution {
    public String longestDiverseString(int a, int b, int c) {
        // Variables to track consecutive 'a', 'b', and 'c' characters added to the result
        int currA = 0, currB = 0, currC = 0;

        // The maximum possible length of the result string will be the total number of characters
        int maxLength = a + b + c;
        int i = 0; // Iterator to control the loop

        StringBuilder sb = new StringBuilder(); // StringBuilder to construct the result string

        // Loop to build the longest possible diverse string
        while (i < maxLength) {
            // Add 'a' if 'a' is not added consecutively twice, and 'a' is greater than or equal to 'b' and 'c', 
            // OR if 'b' or 'c' have already been added twice consecutively
            if (currA != 2 && a >= b && a >= c || a > 0 && (currB == 2 || currC == 2)) {
                sb.append('a'); // Add 'a' to the result
                currA++; // Increment consecutive 'a' count
                currB = 0; // Reset 'b' and 'c' consecutive counts
                currC = 0;
                a--; // Decrement the count of remaining 'a' characters

            // Add 'b' if 'b' is not added consecutively twice, and 'b' is greater than or equal to 'a' and 'c', 
            // OR if 'a' or 'c' have already been added twice consecutively
            } else if (currB != 2 && b >= a && b >= c || b > 0 && (currC == 2 || currA == 2)) {
                sb.append('b'); // Add 'b' to the result
                currB++; // Increment consecutive 'b' count
                currA = 0; // Reset 'a' and 'c' consecutive counts
                currC = 0;
                b--; // Decrement the count of remaining 'b' characters

            // Add 'c' if 'c' is not added consecutively twice, and 'c' is greater than or equal to 'a' and 'b', 
            // OR if 'a' or 'b' have already been added twice consecutively
            } else if (currC != 2 && c >= a && c >= b || c > 0 && (currA == 2 || currB == 2)) {
                sb.append('c'); // Add 'c' to the result
                currC++; // Increment consecutive 'c' count
                currA = 0; // Reset 'a' and 'b' consecutive counts
                currB = 0;
                c--; // Decrement the count of remaining 'c' characters
            }
            i++; // Increment loop iterator
        }

        return sb.toString(); // Return the constructed diverse string
    }
}