Biegral Blog

        题目没有说串的大小，我还在担心呢，但提交后，正确了:

#include <iostream>
using namespace std;

char characterPlusOne(char c)
{
	if('z' == c)
		return 'a';

	return c + 1;
}

char characterMinusOne(char c)
{
	if('a' == c)
		return 'z';

	return c - 1;
}

int main()
{
	char str[100];
	int i, len;

	while(cin >> str)
	{
		len = strlen(str);
		if(0 == len % 2)
		{
			for(i = 0; i < len/2; i++)
			{
				str[i] = characterMinusOne(str[i]);
			}

			for(i = len/2; i < len; i++)
			{
				str[i] = characterPlusOne(str[i]);
			}
		}
		else
		{
			for(i = 0; i < len/2; i++)
			{
				str[i] = characterMinusOne(str[i]);
			}

			for(i = len/2 + 1; i < len; i++)
			{
				str[i] = characterPlusOne(str[i]);
			}
		}

		cout << str << endl;
	}

	return 0;
}