Commit 2323351

authored

Merge pull request knaxus#130 from karimelazzouni/karimelazzouni/bottom-view-binary-tree

Adding bottom view binary tree problem solution

2 parents 79e07ad + 5c42a96 commit 2323351Copy full SHA for 2323351

File tree

+41

-1

lines changed

+41

-1

lines changed

Lines changed: 2 additions & 1 deletion

Lines changed: 39 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,39 @@`
	`1`	`+const Queue = require('../../../Queue');`
	`2`	`+`
	`3`	`+// Determines the bottom view of a binary tree`
	`4`	`+// Takes a BinaryTree as a parameter`
	`5`	`+// Returns an integer array`
	`6`	`+// Time complexity: O(n) where n is the number of nodes in the tree`
	`7`	`+`
	`8`	`+module.exports = function bottomView(binaryTree) {`
	`9`	`+ if (binaryTree == null \|\| binaryTree.root == null) {`
	`10`	`+ return [];`
	`11`	`+ }`
	`12`	`+`
	`13`	`+ // root's horizontal distance = 0`
	`14`	`+ const horizontalDistance = 0;`
	`15`	`+`
	`16`	`+ // create a map to track most recent visited nodes per hd`
	`17`	`+ const hdToNodeValue = new Map();`
	`18`	`+`
	`19`	`+ // perform bfs`
	`20`	`+ const q = new Queue();`
	`21`	`+ q.enqueue([binaryTree.root, horizontalDistance]);`
	`22`	`+`
	`23`	`+ while (q.length() > 0) {`
	`24`	`+ const currentNodeTuple = q.dequeue();`
	`25`	`+ const currentNode = currentNodeTuple[0];`
	`26`	`+ const currentHd = currentNodeTuple[1];`
	`27`	`+ hdToNodeValue.set(currentHd, currentNode.value);`
	`28`	`+`
	`29`	`+ if (currentNode.leftChild != null && currentNode.leftChild.value != null) {`
	`30`	`+ q.enqueue([currentNode.leftChild, currentHd - 1]);`
	`31`	`+ }`
	`32`	`+`
	`33`	`+ if (currentNode.rightChild != null && currentNode.rightChild.value != null) {`
	`34`	`+ q.enqueue([currentNode.rightChild, currentHd + 1]);`
	`35`	`+ }`
	`36`	`+ }`
	`37`	`+`
	`38`	`+ return Array.from(hdToNodeValue.values());`
	`39`	`+};`

Comments

(0)