[LeetCode 77] Combinations [Java]

1. Description Given two integers n and k, return all possible combinations of k numbers out of 1 ... n. 2. Example If n = 4 and k = 2, a soluti...

[LeetCode 67] Add Binary [Java]

1. Description Given two binary strings, return their sum (also a binary string). 2. Example a = "11" b = "1" Return "100". 3.Code public c...

[LeetCode 66] Plus One [Java]

1. Description Given a non-negative integer represented as a non-empty array of digits, plus one to the integer. You may assume the integer do not ...

[LeetCode 65] Valid Number [Java]

1. Description Validate if a given string is numeric. Note: It is intended for the problem statement to be ambiguous. You should gather all require...

[LeetCode 60] Permutation Sequence [Java]

1. Description The set [1,2,3,…,n] contains a total of n! unique permutations. By listing and labeling all of the permutations in order, We get the...

[LeetCode 31] Next Permutation [Java]

1. Description Implement next permutation, which rearranges numbers into the lexicographically next greater permutation of numbers. If such arrange...

[LeetCode 47] Permutations II [Java]

1. Description Given a collection of numbers that might contain duplicates, return all possible unique permutations. 2. Example [1,1,2] have the...

[LeetCode 43] Multiply Strings[Java]

1. Description Given two non-negative integers num1 and num2 represented as strings, return the product of num1 and num2. Note: The length of bo...

[LeetCode 29] Divide Two Integers [Java]

1. Description Divide two integers without using multiplication, division and mod operator. If it is overflow, return MAX_INT. 2. Code public class...

[LeetCode 592] Fraction Addition and Subtraction [Java] [Runtime : 16MS]

1. Description Given a string representing an expression of fraction addition and subtraction, you need to return the calculation result in string ...