Solution.java

class Solution {
    public boolean oneEditAway(String first, String second) {
        int m = first.length(), n = second.length();
        if (m < n) {
            return oneEditAway(second, first);
        }
        if (m - n > 1) {
            return false;
        }
        int cnt = 0;
        if (m == n) {
            for (int i = 0; i < n; ++i) {
                if (first.charAt(i) != second.charAt(i)) {
                    if (++cnt > 1) {
                        return false;
                    }
                }
            }
            return true;
        }
        for (int i = 0, j = 0; i < m; ++i) {
            if (j == n || (j < n && first.charAt(i) != second.charAt(j))) {
                ++cnt;
            } else {
                ++j;
            }
        }
        return cnt < 2;
    }
}