程序员面试题精选100题(46)－对称子字符串的最大长度

题目：输入一个字符串，输出该字符串中对称的子字符串的最大长度。比如输入字符串“google”，由于该字符串里最长的对称子字符串是“goog”，因此输出4。

思路，把每个都看成是对称中心，然后向外扩展。。
[code]
int GetLongestSymmetricalLength_2(char* pString)
{
if(pString == NULL)
return 0;
int symmeticalLength = 1;
char* pChar = pString;
while(*pChar != '\0')
{
// Substrings with odd lengt
char* pFirst = pChar - 1;
char* pLast = pChar + 1;
while(pFirst >= pString && *pLast != '\0' && *pFirst == *pLast)
{
pFirst--;
pLast++;
}
int newLength = pLast - pFirst - 1;
if(newLength > symmeticalLength)
symmeticalLength = newLength;
// Substrings with even length
pFirst = pChar;
pLast = pChar + 1;
while(pFirst >= pString && *pLast != '\0' && *pFirst == *pLast)
{
pFirst--;
pLast++;
}
newLength = pLast - pFirst - 1;
if(newLength > symmeticalLength)
symmeticalLength = newLength;
pChar++;
}
return symmeticalLength;
}
[/code]