请问这个问题怎么解决?

题目内容如下:

img


题目看了半天一直没有思路,希望帮助解决,谢谢!

public boolean transform(String source, String target) {
    if (source.length() != target.length()) {
        return false;
    }
    char[] sChars = source.toCharArray();
    char[] tChars = target.toCharArray();
    int l = 0;
    int h = target.length() - 1;
    for (char sChar : sChars) {
        if (sChar == tChars[l]) {
            l++;
        } else if (sChar == tChars[h]) {
            h--;
        } else {
            return false;
        }
    }
    return true;
}