示例代码:
#include <stdio.h>
#define N 1000000
int main(void)
{
int n = 0 , i = 0;
char arr[N] , tmp[N] , c[2];
scanf("%d",&n);
for (i = 0 ; i < n ; i ++)
{
sprintf(c,"%c",65+i);
sprintf(arr,"%s%s%s",tmp,c,tmp);
sprintf(tmp,"%s",arr);
}
printf("%s",arr);
return 0;
}