LintCode 1784: Decrease To Be Palindrome

LintCode 1784: Decrease To Be Palindrome"/>

LintCode 1784: Decrease To Be Palindrome

1784. Decrease To Be Palindrome

Given a string s with a-z. We want to change s into a palindrome with following operations:

1. change ‘z’ to ‘y’;
2. change ‘y’ to ‘x’;
3. change ‘x’ to ‘w’;
   …
4. change ‘c’ to ‘b’;
5. change ‘b’ to ‘a’;
   Returns the number of operations needed to change s to a palindrome at least.

Example
Example 1:

Input: “abc”
Output: 2
Explanation:

1. Change ‘c’ to ‘b’: “abb”
2. Change the last ‘b’ to ‘a’: “aba”
   Example 2:

Input: “abcd”
Output: 4

解法1：
代码如下：

class Solution {
public:/*** @param s: the string s* @return: the number of operations at least*/int numberOfOperations(string &s) {int n = s.size();if (n <= 1) return 0;int count = 0;int i = 0, j = n - 1;while(i < j) {if (s[i] != s[j]) count += abs(s[j] - s[i]);i++;j--;}return count;}
};