Problem The XOR total of an array is defined as the bitwise XOR of all its elements, or 0 if the array is empty. For example, the XOR total of the array [2,5,6] is 2 XOR 5 XOR 6 = 1. Given an array nums, return the sum of all XOR totals for every subset of nums. Note: Subsets with the same elements should be counted multiple times. ...
Problem Given an integer array nums where every element appears three times except for one, which appears exactly once. Find the single element and return it. You must implement a solution with a linear runtime complexity and use only constant extra space. Examples Example 1: Input : nums = [1, 2, 4, 3, 3, 2, 2, 3, 1, 1] Output : 4 ...
Problem An XOR linked list is a more memory efficient doubly linked list. Instead of each node holding next and prev fields, it holds a field named both, which is an XOR of the next node and the previous node. Implement an XOR linked list; it has an add(element) which adds the element to the end, and a get(index) which returns the node at index. If using a language that has no pointers (such as Python), you can assume you have access to get_pointer and dereference_pointer functions that converts between nodes and memory addresses. ...
Problem Given an array of integers, every element appears twice except for one. Find that single one. Examples Example 1: Input: nums = [2,2,1] Output: 1 Example 2: Input: nums = [4,1,2,1,2] Output: 4 Example 3: Input: nums = [1] Output: 1 ...
Problem Given an integer array nums, in which exactly two elements appear only once and all the other elements appear exactly twice. Find the two elements that appear only once. You can return the answer in any order. You must write an algorithm that runs in linear runtime complexity and uses only constant extra space. Examples Example 1: Input: nums = [1,2,1,3,2,5] Output: [3,5] Explanation: [5, 3] is also a valid answer. ...
Problem Write a function to swap two number in place without temporary variables. Solution Method1 - The XOR or Exclusive trick In C this should work: a ^= b ^= a ^= b; to simplify : a=a^b; b=a^b; a=a^b; ...
Problem You are given two numbers A and B. Write a function to determine the number of bits need to be flipped to convert integer A to integer B. OR A bit flip of a number x is choosing a bit in the binary representation of x and flipping it from either 0 to 1 or 1 to 0. For example, for x = 7, the binary representation is 111 and we may choose any bit (including any leading zeros not shown) and flip it. We can flip the first bit from the right to get 110, flip the second bit from the right to get 101, flip the fifth bit from the right (a leading zero) to get 10111, etc. Given two integers start and goal, return the minimum number of bit flips to convert start to goal. ...