#include <stdio.h> #include <string.h> /*  *判断起始指针，到结束指针的字符串是否对称  */ int IsSymmetrical(char* pBegin, char* pEnd) {     if(pBegin == NULL || pEnd == NULL || pBegin > pEnd)     return 0;     while(pBegin < pEnd)     {     if(*pBegin != *pEnd)         return 0;     pBegin++;     pEnd--;     }     return 1; } /*  *查找最大对称字串长度，时间复杂度是O(n^3)  */ int GetLongestSymmetricalLength(char* pString) {     if(pString == NULL)     return 0;     int symmetricalLength = 1;     char* pFirst = pString;     int length = strlen(pString);     while(pFirst < &pString[length-1])     {     char* pLast = pFirst + 1;     while(pLast <= &pString[length-1])     {         if(IsSymmetrical(pFirst, pLast))         {         int newLength = pLast - pFirst + 1;         if(newLength > symmetricalLength)             symmetricalLength = newLength;         }         pLast++;     }     pFirst++;     }     return symmetricalLength; } int main() {     char* str = "google";     int len = GetLongestSymmetricalLength(str);     printf("%d", len);     return 0; }

#include <stdio.h> #include <string.h> int GetLongestSymmetricalLength(char* pString) {     if(pString == NULL)     return 0;     int symmetricalLength = 1;     char* pChar = pString;     while(*pChar != '\0')     {     //奇数长度对称， 如 aAa     char* left = pChar - 1;     char* right = pChar + 1;     while(left >= pString && *right != '\0' && *left==*right)     {         left--;         right++;     }     int newLength = right - left - 1;   //退出循环是*left!=*right     if(newLength > symmetricalLength)         symmetricalLength = newLength;     //偶数长度对称， 如 aAAa     left = pChar;     right = pChar + 1;     while(left >= pString && *right != '\0' && *left==*right)     {         left--;         right++;     }     newLength = right - left - 1;   //退出循环是*left!=*right     if(newLength > symmetricalLength)         symmetricalLength = newLength;     pChar++;     }     return symmetricalLength; } int main() {     char* str = "google";     int len = GetLongestSymmetricalLength(str);     printf("%d", len);     return 0; }

#include <stdio.h> #include <string.h> int GetLongestSymmetricalLength(char* pString) {     int length = strlen(pString);     char* pNewString = malloc(2*length+2);     int i;     for(i=0; i<length; i++)     {     *(pNewString+i*2) = '#';     *(pNewString+i*2+1) = *(pString+i);     }     *(pNewString+2*length) = '#';     *(pNewString+2*length+1) = '\0';     printf("%s\n", pNewString);     int maxLength = 1;     char* pChar;     for(i=0; i<2*length+2; i++)     {     int newLength = 1;     pChar = pNewString + i;     char* left = pChar-1;     char* right = pChar+1;     while(left>=pNewString && *right!='\0'&& *left==*right)     {         left--;         right++;         newLength++;     }     if(newLength > maxLength)         maxLength = newLength;     }     return maxLength-1; } int main() {     char* str = "google";     int len = GetLongestSymmetricalLength(str);     printf("%d", len);     return 0; }