Codeforces 460D. Little Victor and Set

D. Little Victor and Set
time limit per test:1 second
memory limit per test:256 megabytes
input:standard input
output:standard output

Little Victor adores the sets theory. Let us remind you that a set is a group of numbers where all numbers are pairwise distinct. Today Victor wants to find a set of integers S that has the following properties:

  • for all x  the following inequality holds l ≤ x ≤ r;
  • 1 ≤ |S| ≤ k;
  • lets denote the i-th element of the set S as si; value  must be as small as possible.

Help Victor find the described set.

Input

The first line contains three space-separated integers l, r, k (1 ≤ l ≤ r ≤ 1012; 1 ≤ k ≤ min(106, r - l + 1)).

Output

Print the minimum possible value of f(S). Then print the cardinality of set |S|. Then print the elements of the set in any order.

If there are multiple optimal sets, you can print any of them.

Examples
input
8 15 3
output
1
2
10 11
input
8 30 7
output
0
5
14 9 28 11 16
Note

Operation  represents the operation of bitwise exclusive OR. In other words, it is the XOR operation.

分析:

 分类讨论:

No.1 r-l<=10

直接暴力搜索...

No.2 k=1

此时直接输出l...

No.3 k=2

ans一定是1...(相邻两个xor一下...)

No.4 k>=4

ans一定是0...(相邻4个xor一下...)

No.5 k=3

我们找出最小的m使得2^m大于l...

这样,如果存在三个数x=2^m-1,y=2^m+2^(m-1),z=2^m+2^(m-1)-1,那么就一定可以是0,否则若y>r,ans一定是1...

证明如下:

如果存在m+1能够满足解,那么m也一定可以找到合法解...

因为要使得ans=0,所以第m位一定存在两个1,因此m-1位一定存在1,所以最大值的下界是2^m+2^(m-1)-1,最小值的上界是2^m-1...

代码:

#include<algorithm>
#include<iostream>
#include<cstring>
#include<cstdio>
//by NeighThorn
#define int long long
using namespace std;
//眉眼如初,岁月如故 

int l,r,k,ans,vis;

inline void dfs(int x,int tmp,int lala,int cnt){
    if(lala)
        if(ans>=tmp)
            ans=tmp,vis=lala;
    if(x==r+1||cnt>k)
        return;
    dfs(x+1,tmp,lala,cnt);dfs(x+1,tmp^x,lala|(1<<x-l),cnt+1);
}

signed main(void){
    scanf("%I64d%I64d%I64d",&l,&r,&k);
    if(r-l<=10){
        ans=r;dfs(l,0,0,1);printf("%I64d
",ans);ans=vis;int cnt=0;
        while(ans)
            cnt+=ans&1,ans>>=1;
        printf("%I64d
",cnt);cnt=0;
        while(vis){
            if(vis&1)
                printf("%I64d ",l+cnt);
            cnt++,vis>>=1;
        }
        puts("");
    }
    else if(k==1)
        printf("%I64d
1
%I64d
",l,l);
    else if(k==2){
        puts("1");puts("2");
        if(l&1)
            printf("%I64d %I64d",l+1,l+2);
        else
            printf("%I64d %I64d",l,l+1);
    }
    else if(k>=4){
        puts("0");puts("4");
        if(l&1){
            for(int i=l+1;i<=l+4;i++)
                printf("%I64d ",i);
            puts("");
        }
        else{
            for(int i=l;i<=l+3;i++)
                printf("%I64d ",i);
            puts("");
        }
    }
    else{
        int m,L=1,R=62;
        while(L<=R){
        	int mid=(L+R)>>1;
        	if((1LL
			<<mid)>l)
        		m=mid,R=mid-1;
        	else
        		L=mid+1;
        }
        if(m==0){
        	puts("1");puts("2");
	            if(l&1)
	                printf("%I64d %I64d",l+1,l+2);
	            else
	                printf("%I64d %I64d",l,l+1);
        }
        else{
	        if((1LL<<m)+(1LL<<m-1)>r){
	            puts("1");puts("2");
	            if(l&1)
	                printf("%I64d %I64d",l+1,l+2);
	            else
	                printf("%I64d %I64d",l,l+1);
	        }
	        else{
	            puts("0");puts("3");int x=(1LL<<m)-1,y=(1LL<<m)+(1LL<<m-1),z=(1LL<<m)+(1LL<<m-1)-1;
	            printf("%I64d %I64d %I64d
",x,y,z);
	        }
    	}
    }
    return 0;   
}//Cap ou pas cap. Pas cap.

  


By NeighThorn

原文地址:https://www.cnblogs.com/neighthorn/p/6282495.html