40亿个不重复的数字排序

用bitmap方法，内存只需要 512M左右 

#include <stdio.h>
#include <memory.h>
#define BYTESIZE 8
long long bufferlen =500000000;
char *pBuffer = new char[bufferlen]; 

void setbit(char * p , int posi)
{
    for ( int i = 0 ; i < posi / BYTESIZE ; i++)
    {
        p++;
    }
    *p =  *p | (0x01 << (posi % BYTESIZE)) ;
}
int main()
{
    memset(pBuffer , 0 , bufferlen);
    int arr[] = {  23,12,11,67,89,14,33};
    for ( int i = 0 ; i < 7 ; i++)
    {
        setbit(pBuffer,arr[i]);
    }
    for ( int i = 0 ; i < bufferlen ; i++)
    {
        for ( int j = 0 ; j < BYTESIZE ; j++)
            if ( (*pBuffer & (0x01 << j)) == (0x01 << j) )
                printf("%d" ,  (i )*BYTESIZE + j);
        pBuffer++;
    }
    return 0;
}