DescriptionGiven a list, rotate the list to the right by k places, where k is non-negative. For example:Given 1->2->3->4->5->NULL and k = 2,return 4->5->1->2->3->NULL. Th

DescriptionImplement a basic calculator to evaluate a simple expression string. The expression string contains only non-negative integers, +, -, *, / operators and empty spaces . The integer division

DescriptionThe count-and-say sequence is the sequence of integers beginning as follows:1, 11, 21, 1211, 111221, … 1 is read off as “one 1” or 11.11 is read off as “two 1s” or 21.21 is read off as “one

DescriptionGiven a singly linked list L: L0→L1→…→Ln-1→Ln,reorder it to: L0→Ln→L1→Ln-1→L2→Ln-2→… You must do this in-place without altering the nodes’ values. For example,Given {1,2,3,4}, reorder it to

DescriptionGiven a binary tree, return the bottom-up level order traversal of its nodes’ values. (ie, from left to right, level by level from leaf to root). For example:Given binary tree {3,9,20,#,#,1

DescriptionGiven a binary tree, return the level order traversal of its nodes’ values. (ie, from left to right, level by level). For example:Given binary tree {3,9,20,#,#,15,7}, 3 / 9 20 /

DescriptionGiven a binary tree, return the preorder traversal of its nodes’ values. For example:Given binary tree {1,#,2,3}, 1 2 / 3return [1,2,3]. The original problem is here. The o

DescriptionImplement a basic calculator to evaluate a simple expression string. The expression string may contain open ( and closing parentheses ), the plus + or minus sign -, non-negative integers an

DescriptionDetermine if a Sudoku is valid, according to: Sudoku Puzzles - The Rules. The Sudoku board could be partially filled, where empty cells are filled with the character ‘.’. A partially fille

DescriptionThere are N gas stations along a circular route, where the amount of gas at station i is gas[i]. You have a car with an unlimited gas tank and it costs cost[i] of gas to travel from station