static boolean isOneEditAway(String str1, String str2) {
        if (str1 == null || str2 == null || Math.abs(str1.length() - str2.length()) > 1) {
            return false;
        }

        int lengthDiff = str1.length() - str2.length();
        int edits = 0;
        int i = 0, k = 0;
        for (; i < str1.length() && k < str2.length(); i++, k++) {

            char c1 = str1.charAt(i);
            char c2 = str2.charAt(k);

            if (c1 == c2) {
                continue;
            }

            edits++;

            if (edits > 1) {
                return false;
            }

            if (lengthDiff == 0) {
                continue;
            }

            if (lengthDiff == -1 && k != str2.length() - 1 && c1 == str2.charAt(k + 1)) {
                k++;
            } else if (lengthDiff == 1 && i != str1.length() - 1 && c2 == str1.charAt(i + 1)) {
                i++;
            }
        }

        edits += str1.length() - i;
        edits += str2.length() - k;

        return edits < 2;
    }