CF&&CC百套计划4 Codeforces Round #276 (Div. 1) A. Bits

http://codeforces.com/contest/484/problem/A

 

题意：

询问[a,b]中二进制位1最多且最小的数

 

贪心，假设开始每一位都是1

从高位i开始枚举，

如果当前数>b，且减去1<<i后仍>=a,就减1<<i

当当前数在[a,b]之间时，输出

因为从高位开始减，所以保证当前数是最小的

 

#include<cstdio>
#include<iostream>

using namespace std;

typedef long long LL;

LL bit[61]; 

void read(LL &x)
{
    x=0; char c=getchar();
    while(!isdigit(c)) c=getchar();
    while(isdigit(c)) { x=x*10+c-'0'; c=getchar();  }
} 

int main()
{
    bit[0]=1;
    for(int i=1;i<=60;++i) bit[i]=bit[i-1]<<1; 
    int n;
    scanf("%d",&n);
    LL a,b;
    LL ans;
    while(n--)
    {
        read(a); read(b);
        ans=(1LL<<61)-1;
        for(int i=60;i>=0;--i)
        {
            if(ans>b && ans-bit[i]>=a) ans-=bit[i];
            if(ans>=a && ans<=b) break;
        }
        cout<<ans<<'\n';
    }
}

 

A. Bits

time limit per test

1 second

memory limit per test

256 megabytes

input

standard input

output

standard output

Let's denote as  the number of bits set ('1' bits) in the binary representation of the non-negative integer x.

You are given multiple queries consisting of pairs of integers l and r. For each query, find the x, such that l ≤ x ≤ r, and is maximum possible. If there are multiple such numbers find the smallest of them.

Input

The first line contains integer n — the number of queries (1 ≤ n ≤ 10000).

Each of the following n lines contain two integers li, ri — the arguments for the corresponding query (0 ≤ li ≤ ri ≤ 1018).

Output

For each query print the answer in a separate line.

Examples

input

3
1 2
2 4
1 10

output

1
3
7

Note

The binary representations of numbers from 1 to 10 are listed below:

110 = 12

210 = 102

310 = 112

410 = 1002

510 = 1012

610 = 1102

710 = 1112

810 = 10002

910 = 10012

1010 = 10102

转载于:https://www.cnblogs.com/TheRoadToTheGold/p/8207002.html