程序员面试宝典第一题判断字符串是否相同

bool quick_sort(string &str, int low, int high)
{
    int left = low, right = high;
    char pos = str[left];
    if (low >= high)
        return true;
    while (left < right)
    {
        while (pos <str[right] && left < right)
        {
            right--;
        }
        str[left] = str[right];
        while (left<right&&pos>str[left])
        {
            left++;
        }
        str[right] = str[left];
    }
    str[left] = pos;//两种情况都是最终可以变成这样
    //此时left和right都在一个位置
    //判断该点是否重复（相等的情况）
    if (left > low&&str[left] == str[left - 1])
    {
        return false;
    }
    if (right < high&&str[right] == str[right + 1])
    {
        return false;
    }
    return quick_sort(str,low, left - 1) &&quick_sort(str, left+1,high);
}
bool check_difference(string str)
{
    int length = str.size();
    return quick_sort(str, 0, length - 1);
}