C++随机生成整数测试磁盘文件排序

C++随机生成整数测试磁盘文件排序

#include <iostream>
#include <time.h>
#include <assert.h>

using namespace std;

const int size=10000000;
int num[size];

int main()
{
  FILE *fp=fopen("data.txt","w");
  assert(fp);

  for(int n=1; n <= size; n++)
  {
     num[n]=n;
  }
  
  srand((unsigned)time(NULL));

  for (int n=0; n < size;n++)
  {
	  int i=(rand()*RAND_MAX + rand())%10000000;
	  int j=(rand()*RAND_MAX + rand())%10000000;
	  swap(num[i],num[j]);
  }

  for (int n=0; n < size; n++)
  {
	  fprintf(fp,"%d ",num[n]);
  }

  fclose(fp);

  return 0;
}