Array LeetCode 75

/* Pseudocode: Merge Strings Alternately
FUNCTION mergeStringsAlternately(string1, string2)
    INITIALIZE result as an empty string
    INITIALIZE i = 0
    INITIALIZE j = 0
    WHILE i < length(string1) OR j < length(string2)
        IF i < length(string1)
            APPEND string1[i] to result
            INCREMENT i
        ENDIF
        IF j < length(string2)
            APPEND string2[j] to result
            INCREMENT j
        ENDIF
    ENDWHILE
    RETURN result
END FUNCTION

*/


class Solution {
    public static void main(String[] args) {
        String word1 = "abc";
        String word2 = "pqr";
        Solution solution = new Solution();
        System.out.println(solution.mergeAlternately(word1, word2));
    }
    
    public String mergeAlternately(String word1, String word2) {
        StringBuilder result = new StringBuilder();
        int i = 0, j = 0;
        int len1 = word1.length(), len2 = word2.length();
        
        while (i < len1 || j < len2) {
            if (i < len1) {
                result.append(word1.charAt(i));
                i++;
            }
            
            if (j < len1) {
                result.append(word2.charAt(j));
                j++;
            }
        }
        return result.toString();
    }
}