DescriptionGiven an array of integers, every element appears three times except for one. Find that single one. Note:Your algorithm should have a linear runtime complexity. Could you implement it witho

DescriptionGiven an array of integers, every element appears twice except for one. Find that single one. Note:Your algorithm should have a linear runtime complexity. Could you implement it without usi

DescriptionDesign a stack that supports push, pop, top, and retrieving the minimum element in constant time. push(x) – Push element x onto stack. pop() – Removes the element on top of the stack. top(

DescriptionReverse a singly linked list. The original problem is here. The original code is here.

DescriptionThe original problem is here. The original code is here.

Descriptionnvert a binary tree. 4 / 2 7 / \ / 1 3 6 9to 4 / 7 2 / \ / 9 6 3 1 The original problem is here. The original code is here.

DescriptionGiven a binary tree, check whether it is a mirror of itself (ie, symmetric around its center). For example, this binary tree is symmetric: 1 / 2 2 / \ / 3 4 4 3But the follow

DescriptionGiven a non-negative number represented as an array of digits, plus one to the number. The digits are stored such that the most significant digit is at the head of the list. The original pr

DescriptionGiven two binary trees, write a function to check if they are equal or not. Two binary trees are considered equal if they are structurally identical and the nodes have the same value. The o

DescriptionGiven a sorted array, remove the duplicates in place such that each element appear only once and return the new length. Do not allocate extra space for another array, you must do this in pl