enter image description hereclass Solution {

    public:
        string mergeAlternately(string word1, string word2) {
        int len1 = word1.length();
        int len2 = word2.length();
        string ans;
        for (int i = 0, j = 0, k = 0; i < word1.length() + word2.length(); i++) {
            if (i % 2 == 0 && j < len1 || k == len2) {
                ans += word1[j];
                j++;
            }
            if (i % 2 == 1 && k < len2 || j == len1) {
                ans += word2[k];
                k++;
            }
        }
        return ans;
    }

    };

I checked if I am appending null character but it is less than Len so I have no idea what is wrong with the code.