C语言 用指针统计二维字符数组中的最大字符串

#include<string.h>
#include<stdlib.h>
char * find_max_string(char a[][300],int n)
 {
     char *pmax; 
    int i, j = 0, k;
    for (i = 0; i < n; i++)
    {
        k = strcmp(a[j],a[i]);
        if (k < 0)
        {
            j = i;
        }
    }
    pmax = &a[j-1][300];
    return pmax;
 } 
int main()
{  
    char a[10][300]={"afsdfas","asdfasdf","werqwrqwe","asfdasdfatewt"},*p;
    int n=10;
    p=find_max_string(a,n);
    puts(p);
    return 0;
 }