LeetCode Find the Derangement of An Array In combinatorial mathematics, a derangement is a permutation of the elements of a set, such that no element appears in its original position. There's originally an array consisting of n integers from 1... Read More

# Tag Archives: 数论

# LeetCode Next Greater Element III

LeetCode Next Greater Element III Given a positive 32-bit integer n, you need to find the smallest 32-bit integer which has exactly the same digits existing in the integer n and is greater in value than n. If no such positive 32-bit integer exists, you... Read More

# LeetCode Integer Replacement

LeetCode Integer Replacement Given a positive integer n and you can do operations as follow: If n is even, replace n with n/2. If n is odd, you can replace n with either n + 1 or n - 1. What is the minimum number of replacements needed for n to... Read More

# hihoCoder 1518-最大集合

hihoCoder 1518-最大集合 #1518 : 最大集合 时间限制:10000ms 单点时限:1000ms 内存限制:256MB 描述 给定一个1-N的排列A, A, ... A，定义集合S = {A, A], A]] ...... Read More

# hihoCoder 1493-歌德巴赫猜想

hihoCoder 1493-歌德巴赫猜想 #1493 :... Read More

# LeetCode 132 Pattern

LeetCode 132 Pattern Given a sequence of n integers a1, a2, ..., an, a 132 pattern is a subsequence ai, aj, ak such that i < j < k and ai < ak < aj. Design an algorithm that takes a list of n numbers as input and checks whether there is a... Read More

# LeetCode Water and Jug Problem

LeetCode Water and Jug Problem You are given two jugs with capacities x and y litres. There is an infinite amount of water supply available. You need to determine whether it is possible to measure exactly z litres using these two jugs. If z liters of... Read More

# LeetCode Perfect Number

LeetCode Perfect Number We define the Perfect Number is a positive integer that is equal to the sum of all its positive divisors except itself. Now, given an integer n, write a function that returns true when it is a perfect number and false when it is... Read More

# LeetCode Maximum XOR of Two Numbers in an Array

LeetCode Maximum XOR of Two Numbers in an Array Given a non-empty array of numbers, a0, a1, a2, … , an-1, where 0 ≤ ai < 231. Find the maximum result of ai XOR aj, where 0 ≤ i, j < n. Could you do this in O(n) runtime? Example: Input:... Read More

# LeetCode Base 7

LeetCode Base 7 Given an integer, return its base 7 string representation. Example 1: Input: 100 Output: "202" Example 2: Input: -7 Output: "-10" Note: The input will be in range of... Read More