/*
73.对称字符串的最大长度（字符串）。
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。
*/#include <stdio.h>
#include <string.h>bool issymmetry(char * in, int len) //判断字符串是否对称
{int i, j;for(i = 0, j = len - 1; i < j ; i++, j--){if(in[i] != in[j]){return false;}}return true;
}int maxSubSymLen(char * in, int len)
{int nlen;for(nlen = len; nlen >= 1; nlen--) //按长度循环
    {if(nlen == 1){return 1;}else{int i;for(i = 0; i <= len - nlen; i++) //首字母位置循环
            {if(issymmetry(in + i, nlen)){for(int j = i; j < i + nlen; j++){printf("%c ", in[j]);}return nlen;}}}}
}int main()
{char a[40] = "asdgjoalsgjeslhfelgjdjglejf";int ans = maxSubSymLen(a, strlen(a));return 0;
}

/*
取得所有对称子串的最大长度
时间复杂度： O(n^2)
*/int GetLongestSymmetricalLength(char* pString)
{if(pString == NULL)return 0;int symmeticalLength = 1;char* pChar = pString;while(*pChar != '\0'){// Substrings with odd lengthchar* left = pChar - 1;char* right = pChar + 1;while(left >= pString && *right != '\0' && *left == *right){left--;right++;}int newLength = right - left - 1;    //退出while循环时，*left != *rightif(newLength > symmeticalLength)symmeticalLength = newLength; // Substrings with even lengthleft = pChar;right = pChar + 1;while(left >= pString && *right != '\0' && *left == *right){left--;right++;}newLength = right - left - 1;        //退出while循环时，*left != *rightif(newLength > symmeticalLength)symmeticalLength = newLength;pChar++;}return symmeticalLength;
}

#include <stdio.h>#define M 110010char b[M],a[M<<1];
int p[M<<1];int Min(int a,int b)
{return a<b?a:b;
}int main(void)
{int i,n,id,MaxL,MaxId;while(scanf("%s",&b[1])!=EOF){MaxL=MaxId=0;for(i=1;b[i]!='\0';i++){a[(i<<1)]=b[i];a[(i<<1)+1]='#';}a[0]='?';a[1]='#';n=(i<<1)+2;a[n]=0;MaxId=MaxL=0;for(i=1;i<n;i++){if(MaxId>i){p[i]=Min(p[2*id-i],MaxId-i);}else{p[i]=1;}while(a[i+p[i]]==a[i-p[i]]){p[i]++;}if(p[i]+i>MaxId){MaxId=p[i]+i;id=i;}if(p[i]>MaxL){MaxL=p[i];}}printf("%d\n",MaxL-1);}return 0;
}