#include<stdio.h>  #include <time.h>  #include "iostream"  #include <math.h>  #define  N  53  using namespace  std;      //print array  void display(int *a)  {         for (int i =0;i<N;i++)         {             cout<<" "<<a[i]<<" ";         }             }      int  main(void)  {              int b[N],a[N];      for (int i =0;i<N;i++)      {          b[i] = i+1;      }      //  random(a);      srand((unsigned)time(NULL));      int MaxIndex = N;      for ( i= 0;i<N;i++)      {                  //           int index = (int)rand()%MaxIndex;//随机一个 0 - 52的index          a[i] = b[index];        //随机到的数字给a[i],i from 0 to N-1          b[index] = b[MaxIndex-1];          MaxIndex--;              }          display(a);      return 0;  }