//返回最長的對稱字串的長度，如google，對稱字串是goog，最大長度為4
int symStr(char* source)
{
	if('\0' == *source)
		return 0;
	int maxLength = 1;
	char* current = source;
	while('\0' != *current)
	{
		int max1 = 0;
		int symIndex = 0; // 對稱遊標
		//(1) googllgox,對稱字元個數為偶數,比如這樣返回6,此時current + i + 1
		while('\0' != *(current - symIndex - 1) && '\0' != *(current + symIndex) &&
			*(current - symIndex - 1) == *(current + symIndex))
		{
			max1 += 2;
			symIndex++;
		}
		maxLength = max(max1, maxLength);
		max1 = 1;
		symIndex = 1;
		//(2)baidudiac,對稱字元個數為奇數,比如這樣返回7
		while('\0' != *(current - symIndex) && '\0' != *(current + symIndex) &&
			*(current - symIndex) == *(current + symIndex))
		{
			max1 += 2;
			symIndex++;
		}
		maxLength = max(max1, maxLength);
		++current;
	}
	return maxLength;
}