鏈接 sel time cau int another logs 題目 there

題目鏈接：http://acm.hdu.edu.cn/showproblem.php?pid=3949

XOR

Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 4731 Accepted Submission(s): 1658

Problem Description XOR is a kind of bit operator, we define that as follow: for two binary base number A and B, let C=A XOR B, then for each bit of C, we can get its value by check the digit of corresponding position in A and B. And for each digit, 1 XOR 1 = 0, 1 XOR 0 = 1, 0 XOR 1 = 1, 0 XOR 0 = 0. And we simply write this operator as ^, like 3 ^ 1 = 2,4 ^ 3 = 7. XOR is an amazing operator and this is a question about XOR. We can choose several numbers and do XOR operatorion to them one by one, then we get another number. For example, if we choose 2,3 and 4, we can get 2^3^4=5. Now, you are given N numbers, and you can choose some of them(even a single number) to do XOR on them, and you can get many different numbers. Now I want you tell me which number is the K-th smallest number among them.

Input First line of the input is a single integer T(T<=30), indicates there are T test cases.
For each test case, the first line is an integer N(1<=N<=10000), the number of numbers below. The second line contains N integers (each number is between 1 and 10^18). The third line is a number Q(1<=Q<=10000), the number of queries. The fourth line contains Q numbers(each number is between 1 and 10^18) K1,K2,......KQ.

Output For each test case,first output Case #C: in a single line,C means the number of the test case which is from 1 to T. Then for each query, you should output a single line contains the Ki-th smallest number in them, if there are less than Ki different numbers, output -1.

Sample Input 2 2 1 2 4 1 2 3 4 3 1 2 3 5 1 2 3 4 5

Sample Output Case #1: 1 2 3 -1 Case #2: 0 1 2 3 -1 Hint If you choose a single number, the result you get is the number you choose. Using long long instead of int because of the result may exceed 2^31-1.

Author elfness

Source 2011 Multi-University Training Contest 11 - Host by UESTC

Recommend xubiao | We have carefully selected several similar problems for you: 3946 3948 3947 3945 3944 題目大意：輸入t，t組樣例，輸入n，有n個數，接下來為n個數的值，輸入q，代表q次詢問，接下來q個數，要你求出第k小的數 學習：https://www.cnblogs.com/vb4896/p/6149022.html 思路：這一題顯然是線性基來做，首先先把最大線性無關組，也就是線性基求出來，然後題目要求是要你求出第k小的數，在線性基的基礎上，我們可以稍微改造一下，就是保證只有b[i]的第i位是1，其它的第i 位都為0，有了這個性質，我們要求第k小的數，就是把k用二進制表示，如果第j為是1的話，就異或第j個線性基的向量，這裏可能需要的讀者多想一下，（因為都是二進制表示，具體的我也描述不出來） 看代碼：

#include<iostream>
#include<string.h>
#include<map>
#include<cstdio>
#include<cstring>
#include<stdio.h>
#include<cmath>
#include<ctype.h>
#include<math.h>
#include<algorithm>
#include<set>
#include<queue>
typedef long long ll;
using namespace std;
const ll mod=1e9+7;
const int maxn=1e4+10;
const int maxk=5e3+10;
const int maxx=1e4+10;
const ll maxe=1000+10;
#define INF 0x3f3f3f3f3f3f
#define Lson l,mid,rt<<1
#define Rson mid+1,r,rt<<1|1
ll a[maxn],b[100];
ll m,k;
void guass(int n)
{
    memset(b,0,sizeof(b));
    for(int i=0;i<n;i++)
    {
        for(int j=63;j>=0;j--)
        {
            if((a[i]>>j)&1)
            {
                if(!b[j])
                {
                    b[j]=a[i];
                    break;
                }
                else
                {
                    a[i]^=b[j];
                }
            }
        }
    }
    for(int i=63;i>=0;i--)
    {
        if(!b[i]) continue;
        for(int j=i+1;j<=63;j++)
        {
            if((b[j]>>i)&1) b[j]^=b[i];//為了使得只有b[i]的第i為1，其它的都不為1
        }
    }
    m=0;
    for(int i=0;i<=63;i++) if(b[i]) b[m++]=b[i];
}
int main()
{
    int t,ca=1,n,q;
    cin>>t;
    while(t--)
    {
        cin>>n;
        printf("Case #%d:\n",ca++);
        for(int i=0;i<n;i++)
        {
            cin>>a[i];
        }
        guass(n);
        cin>>q;
        while(q--)
        {
            ll ans=0;
            cin>>k;
            if(n!=m) k--;//代表可以是0
            if(k>=(1ll<<m)) cout<<"-1"<<endl;
            else
            {
                for(int i=0;i<=63;i++) if((k>>i)&1) ans^=b[i];
                cout<<ans<<endl;
            }
        }
    }
    return 0;
}

hdu3949(線性基,求第k小的異或和