hdu 5014 贪心+位处理

#include <iostream>
#include <stdio.h>
#include <string>
#include <string.h>
#include <algorithm>
const int N=1e5+100;
using namespace std;
typedef long long ll;
int a
;
int b
;

int main()
{
    int n;
    while(scanf("%d",&n)!=EOF)
    {
        memset(b,-1,sizeof(b));
        for(int i=0;i<=n;i++)scanf("%d",&a[i]);
        ll sum=0;

        for(int i=n;i>=0;i--)
        {
           if(b[i]!=-1)continue;
           int tmp=i,ans=0,cnt=1;
           while(tmp)
           {
             if((tmp&1)==0)ans+=cnt;
             tmp>>=1;
             cnt*=2;
           }
          sum+=2*(i^ans);
          b[i]=ans;
          b[ans]=i;
        }
        printf("%I64d\n",sum);
        for(int i=0;i<=n;i++)
        {
          if(i==0)printf("%d",b[a[i]]);
          else printf(" %d",b[a[i]]);
        }
        printf("\n");
    }
    return 0;
}