Description
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.
Sample Input
3
1 2
2 4
1 10
1
3
7
Hint
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
一个纯粹的贪心，可以按位一步一步贪。
Description
Paul hates palindromes. He assumes that string s is tolerable if each its character is one of the first p letters of the English alphabet and sdoesn‘t contain any palindrome contiguous substring of length 2 or more.
Paul has found a tolerable string s of length n. Help him find the lexicographically next tolerable string of the same length or else state that such string does not exist.
Input
The first line contains two space-separated integers: n and p (1 ≤ n ≤ 1000; 1 ≤ p ≤ 26). The second line contains string s, consisting of n small English letters. It is guaranteed that the string is tolerable (according to the above definition).
Output
If the lexicographically next tolerable string of the same length exists, print it. Otherwise, print "NO" (without the quotes).
Sample Input
3 3
cba
NO
3 4
cba
cbd
4 4
abcd
abda
Hint
String s is lexicographically larger (or simply larger) than string t with the same length, if there is number i, such that s1 = t1, ..., si = ti,si + 1 > ti + 1.
The lexicographically next tolerable string is the lexicographically minimum tolerable string which is larger than the given one.
A palindrome is a string that reads the same forward or reversed.
一道构造题，构造题真是。。。。。
要做这道题，有个结论非常重要，那就是只有“部分对称” ， 才会有可能性造成“整体堆成”，所以只要破坏所有“部分对称“，就行了。
而部分对称只有两种形式”aa” ， “aba”
Description
The new ITone 6 has been released recently and George got really keen to buy it. Unfortunately, he didn‘t have enough money, so George was going to work as a programmer. Now he faced the following problem at the work.
Given a sequence of n integers p1, p2, ..., pn. You are to choose k pairs of integers:
in such a way that the value of sum is maximal possible. Help George to cope with the task.
Input
The first line contains three integers n, m and k(1 ≤ (m × k) ≤ n ≤ 5000). The second line contains n integers p1, p2, ..., pn(0 ≤ pi ≤ 109).
Output
Print an integer in a single line — the maximum possible value of sum.
Sample Input
5 2 1
1 2 3 4 5
9
7 1 3
2 10 7 18 5 33 0
61
原文：http://www.cnblogs.com/get-an-AC-everyday/p/4693008.html