java algorithm interview questions

"105-construct binary tree from preorder and inorder traversal (construction of two-fork trees via pre-order and middle-order traversal)""leetcode-Interview algorithm classic-java Implementation" "All topics Directory Index"Original QuestionGiven Preorder and inorder traversal of a tree, construct the binary tree.　　Note:Assume that duplicates does not exist in th

"203-remove Linked list Elements (remove elements from single-linked list)""leetcode-Interview algorithm classic-java Implementation" "All topics Directory Index"code Download "Https://github.com/Wang-Jun-Chao"Original QuestionRemove all elements from a linked list of integers, that has value Val.ExampleGiven: 1 --> 2 --> 6 --> 3 --> 4 --> 5 --> 6 , val = 6Return

"027-remove element (removes elements from an array)""leetcode-Interview algorithm classic-java Implementation" "All topics Directory Index"Original QuestionGiven an array and a value, remove all instances of that value in place and return the new length.The order of elements can be changed. It doesn ' t matter what are you leave beyond the new length.Main TopicG

"025-reverse Nodes in K-group (a set of K nodes in a single linked list is reversed)""leetcode-Interview algorithm classic-java Implementation" "All topics Directory Index"Original QuestionGiven A linked list, reverse the nodes of a linked list K at a time and return its modified list.If the number of nodes is not a multiple of k then left-out nodes in the end sh

"061-rotate list (revolving single linked list)""leetcode-Interview algorithm classic-java Implementation" "All topics Directory Index"Original QuestionGiven 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 k = 2 and,Return 4->5->1->2->3->NULL .Main TopicRotate a single linked list to the right, rotat

"113-path Sum II (Path and II)""leetcode-Interview algorithm classic-java Implementation" "All topics Directory Index"Original QuestionGiven a binary tree and a sum, find all root-to-leaf paths where each path ' s sum equals the Given sum.For example:Given the below binary tree and sum = 22, 5 4 8 / 11

"102-binary Tree Level Order traversal (binary tree sequence traversal)""leetcode-Interview algorithm classic-java Implementation" "All topics Directory Index"Original QuestionGiven 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 /

"104-maximum Depth of binary tree (maximum depth of binary trees)""leetcode-Interview algorithm classic-java Implementation" "All topics Directory Index"Original QuestionGiven a binary tree, find its maximum depth.The maximum depth is the number of nodes along, the longest path from the root node to the farthest leaf node.Main TopicGiven a two-pronged tree, ask f

"101-symmetric tree (symmetric trees)""leetcode-Interview algorithm classic-java Implementation" "All topics Directory Index"Original QuestionGiven a binary tree, check whether it is a mirror of the itself (ie, symmetric around its center).For example, this binary tree is symmetric: 1 2 \ 3 4 4 3But the following are not: 1 2 2 \ 3 3

"111-minimum Depth of Binary tree (minimum depth of binary trees)""leetcode-Interview algorithm classic-java Implementation" "All topics Directory Index"Original QuestionGiven a binary tree, find its minimum depth.The minimum depth is the number of nodes along, the shortest path from the root node to the nearest leaf node.Main TopicGiven a two-fork tree to find t

"107-binary Tree Level Order Traversal II (binary tree Sequence Traversal II)""leetcode-Interview algorithm classic-java Implementation" "All topics Directory Index"Original QuestionGiven a binary tree, return the bottom-up level order traversal of its nodes ' values. (ie, from the left-to-right, the level by level from the leaf to root).For example:Given binary

"108-convert Sorted array to binary Search tree (sort array into balanced binary tree)""leetcode-Interview algorithm classic-java Implementation" "All topics Directory Index"Original QuestionGiven an array where elements is sorted in ascending order, convert it to a height balanced BST.Main TopicGiven an ascending two-prong tree, convert it to a highly balanced t

"083-remove duplicates from Sorted list (to remove duplicate nodes in a sorted single-linked list)""leetcode-Interview algorithm classic-java Implementation" "All topics Directory Index"Original QuestionGiven a sorted linked list, delete all duplicates such this each element appear only once.For example,Given 1->1->2 , return 1->2 .Given 1->1->2->3->3 , return 1-

"098-validate binary search Tree""leetcode-Interview algorithm classic-java Implementation" "All topics Directory Index"Original QuestionGiven a binary tree, determine if it is a valid binary search tree (BST).Assume a BST is defined as follows:The left subtree of a node contains only nodes with keys less than the node ' s key.The right subtree of a node contains

"119-pascal ' s Triangle II (Pascal triangle (Yang Hui triangle) II)""leetcode-Interview algorithm classic-java Implementation" "All topics Directory Index"Original QuestionGiven an index k, return the kth row of the Pascal ' s triangle.For example, given k = 3,Return [1,3,3,1] .　　Note:Could optimize your algorithm to

"226-invert binary tree (reverse two fork)""leetcode-Interview algorithm classic-java Implementation" "All topics Directory Index"code Download "Https://github.com/Wang-Jun-Chao"Original QuestionInvert a binary tree. 4 / 2 \ 1 3 6 9To 4 / 7 \ 9 6 3 1Main TopicFlips a binary tree.Thinking of solving problemsFor each node, th

"144-binary Tree Preorder Traversal (binary tree non-recursive pre-sequence traversal)""leetcode-Interview algorithm classic-java Implementation" "All topics Directory Index"Original QuestionGiven 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] .Note:recursive solu

"023-merge K Sorted Lists (combined with k-lined single-linked list)""leetcode-Interview algorithm classic-java Implementation" "All topics Directory Index"Original QuestionMerge K sorted linked lists and return it as one sorted list. Analyze and describe its complexity.Main TopicCombine k rows of single linked lists. Analyze and describe its complexity.Thinking

"101-symmetric tree (symmetric trees)""leetcode-Interview algorithm classic-java Implementation" "All Topics folder Index"Original QuestionGiven a binary tree, check whether it is a mirror of the itself (ie, symmetric around its center).For example, this binary tree is symmetric: 1 2 \ 3 4 4 3But the following are not: 1 2 2 \ 3 3Not

"106-construct binary tree from Inorder and postorder traversal (construct two-fork trees via middle order and post-sequence traversal)""leetcode-Interview algorithm classic-java Implementation" "All Topics folder Index"Original QuestionGiven Inorder and Postorder traversal of a tree, construct the binary tree.　　Note:Assume that duplicates does not exist in the t