打乱数组顺序

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
int * neworder(int len);

int main()
{   
    int a[7] = {45, 23, 12, 56, 4, 78, 56};
    int i = 0;
    int *b = neworder(7);
    
    for(i = 0; i < 7; i++)
    {
        printf("%d ", a[b[i]]);

    }
    printf("
");

    free(b);//释放内存
    system("pause");
    return 0;
}

int * neworder(int len)//新的下标顺序，好繁琐，待优化
{  
   int temp = 0, count = 0, num = 0;
   int i = 0;
   int *b = NULL;

   srand((unsigned)time(NULL));
   b = (int*)malloc(sizeof(int) * len);
 
   while(count < len)
   {
      temp = rand() % len;
      if(0 == count)
      {   
          b[0] = temp;
          count++;
      }

      num = 0;
      for(i = 0; i < count; i++)
      {
          if(b[i] == temp)
          {                 
              break;
          }
          else
          {
             num++;//记录不相等的个数
          }
      }
     
      if(num == count)
      {
          b[count] = temp;
          count++;
      }
   }

   return b;
}