#include<iostream>
using namespace std;
#include<cstdlib>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>

const int maxN=500002;
int result[maxN];
bool used[maxN];
int main()
{
    int n;
    long m;
    int i,j,k;
    while(scanf("%d%ld",&n,&m)&&!(-1==n&&-1==m))
    {
          memset(used,false,sizeof(bool)*(n+1));
          for(i=0;i<n;++i)
              result[i]=i+1;
          int restN=ceil((-3.0+sqrt(9.0+8.0*m))/2.0);
          int tempRestN=restN+1;
          int need=m-(tempRestN%2==0?tempRestN/2*(tempRestN-1):(tempRestN-1)/2*tempRestN);
          int nbase=n-restN-1;
          int preIndex=n-2-restN;
          int value=need+nbase;
          result[preIndex]=value;
          for(i=0;i<=preIndex;++i)
          {
              used[result[i]-1]=true;
          }
          int start=n-1;
          for(i=preIndex+1;i<n;++i)
          {
              while(used[start])
                    --start;
              result[i]=start+1;
              used[start]=true;
          }
          for(i=0;i<n-1;++i)
          {
              printf("%d",result[i]);
              printf(" ");
          }
          printf("%d\n",result[n-1]);
    }
    return 0;
}

• 改成C++就快了 (8) longpo 2009-10-01 13:05:04