Phone interview question # 1: Given an array (for example, [ 1, 0, 2, 0, 0, 3, 4 ]), implement methods that 1. returns the number of non-zero elements (4) 2. moves the non-zero elements to the beginning of the array (the rest of the elements don't matter) -> both [ 1, 2, 3, 4, 0, 0, 0] and [ 4, 1, 3, 2, X, Y, Z ] are valid
Given an array, without using extra space, move all zeros to the end and no-zeros to the beginning. The function should return the number of non-zeros.
Verify that a binary search tree is indeed a binary search tree.
given an array of words, how to eliminate the duplicates? You have a simple tree structure Ⓐ and its clone ⓐ. Each node in the tree has a pointer to it's parent as well as an array of its children. Given an original tree's node Ⓑ and cloned tree ⓐ, implement a method that returns ⓑ (the clone of Ⓑ). (Imagine finding the matching UIButton/UISlider/UIView in a separate cloned view controller.) Original Ⓐ ┏━┻━━┓ ◯ ◯ ┏┻┓ ┏━╋━┓ ◯ ◯ ◯ ◯ ◯ ┏┻┓ ┃ ◯ Ⓑ ◯ Clone ⓐ ┏━┻━━┓ ◯ ◯ ┏┻┓ ┏━╋━┓ ◯ ◯ ◯ ◯ ◯ ┏┻┓ ┃ ◯ ⓑ ◯
1. Given a 3 array like below NSArray *a = [1,3,4,5]; NSArray *b = [-1,3,0,9]; NSArray *c = [0,31,32,22,6]; Find the elements from the three array which existing in atleast 2 arrays. Eg: [3, 0] Because 3 is presented in array a, b and 0 is presented in array b, c respectively. -(NSArray)find2ElementsAtleastPresentIn2Arrays:(NSArray*)aList b::(NSArray*)bList c::(NSArray*)cList{ // -- your code here. }
iOS developers have a "dispatch_after(when, queue, block)" Grand Central Dispatch (GCD) function they can utilize but once it's set up, these calls can not be easily cancelled. Describe how you might implement a more convenient version of this named "cancellable_dispatch_after"
Can write a function which inputs two ints and check if it is 3 it should return 6 if input is 6 return 3, without using any condition.
Return the head node of the singly linked list with each pair of nodes swapped. If there is a last odd node leave it in place. Example: Input: 1 -> 2 -> 3 -> 4 -> 5 Output: 2 -> 1 -> 4 -> 3 -> 5
The same list, back to inorder binary tree
The same usual customer service questions. Same sort of questions that are on the application
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