用 简单c语言 ~求出最长回文子串

#include<stdlib.h>
#include<stdio.h>
int main()
{
    
    
    char* longestPalindrome(char* s);
    char s[] = "erwwr";//任写 
    char* c = longestPalindrome(s);
    printf("%s\n", c);
}
char* longestPalindrome(char* s) {
    
    
    int expend1 = 0, max1 = 0;
    int index1 = 0, index2 = 0;//记录下最大子串的长度 
    int count1 = 0, maxLength1 = 0;
    int k1, i, g1;
    int count_x = 0;//计算出字符串长度 
    /*计算奇数时的情况*/
    for (i = 0; s[i] != '\0'; i++, count_x++)
    {
    
    
        k1 = i, g1 = i;//分别从中心位置扩散
        count1 = 0; expend1 = 0;
        while ((s[k1] == s[g1]) && s[k1] && g1 >= 0)
        {
    
    
            ++count1; //计算字符个数 
            ++expend1;
            k1 = i + expend1; //向后扩散 
            g1 = i - expend1; //向前扩散 

        }
        if (count1 > max1) {
    
    
            max1 = count1;
            index1 = g1 + 1;
            index2 = k1 - 1;
            maxLength1 = index2 - index1 + 1;//求出最大长度 
        }
    }
    /*计算偶数时的情况*/
    int count2 = 0, expend2 = 0, max2 = 0, maxLength2 = 0;
    int index3 = 0, index4 = 0;//记录下最大子串的长度
    int j, g2, k2;
    for (j = 0; j < count_x - 1; j++) {
    
    
        g2 = j, k2 = j + 1;//分别从两个位置扩散 
        count2 = 0; expend2 = 0;
        while ((s[g2] == s[k2]) && g2 >= 0 && s[k2])
        {
    
    
            ++count2;
            ++expend2;
            g2 = j - expend2;  //向后扩散 
            k2 = j + 1 + expend2;//向前扩散 
        }
        if (count2 > max2) {
    
    
            max2 = count2;
            index3 = g2 + 1;
            index4 = k2 - 1;
            maxLength2 = index4 - index3 + 1;//求出最大长度 
        }
    }
    /*判断奇数还是偶数子串大*/
    int y = 0, h;
    if (max1 > max2)
    {
    
    
        char* c = (char*)malloc(maxLength1 + 1);
        if (c) {
    
    
               for (h = index1; h <= index2; h++)
               {
    
    
                    c[y++] = s[h];
               }
               c[y] = '\0';
        }
        return c;
    }
    else {
    
    
        char* c = (char*)malloc(maxLength2 + 2);
        if (c) {
    
    
                for (h = index3; h <= index4; h++)
                {
    
    
                      c[y++] = s[h];
                }
                c[y] = '\0';
        }
        return c;
    }
}