[Leetcode] [JavaScript] Lowest Common Ancestor of a Binary Tree

Lowest Common Ancestor of a Binary Tree

Given a binary tree, find the lowest common ancestor (LCA) of the Given nodes in the tree.

According to the definition of the LCA in Wikipedia: "The lowest common ancestor is defined between," nodes V and W as the L Owest node in T, have both V and W as descendants (where we allow a node to be a descendant of itself). "

        _______3______       /                  ___5__          ___1__   /      \        /         6      _2       0       8         /           7   4

For example, the lowest common ancestor (LCA) of nodes and are 5 1 3 . Another example is LCA of nodes 5 4 5 and are, since a node can be a descendant of itself according to the L CA definition.

https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree/

The ugly solution of using the previous question can be too.

Http://www.cnblogs.com/Liok3187/p/4641389.html

1 /**2 * Definition for a binary tree node.3 * Function TreeNode (val) {4 * This.val = val;5 * This.left = This.right = null;6  * }7  */8 /**9 * @param {TreeNode} rootTen * @param {TreeNode} p One * @param {TreeNode} q A * @return {TreeNode} -  */ - varLowestcommonancestor =function(Root, p, q) { the     vartarget = [], res, isfound =false; - Target.push (p.val); - Target.push (q.val); - Findlca (root); +     returnRes; -  +     functionFINDLCA (node) { A         if(isfound) { at             return []; -         } -  -         varCandidates = []; -         if(Node.left!==NULL){ -             varleft =Findlca (node.left); inleft =Compareval (left); -             if(left = = =true){ tores =Node.left; +Isfound =true; -                 return []; the}Else if(Left.length = = 1){ *candidates=Left ; $             }Panax Notoginseng         } -  the         if(Node.right!==NULL&&!isfound) { +             varright =Findlca (node.right); A             if(right && right.length = = = 1){ theCandidates.push (right[0]); +             } -right =Compareval (candidates); $             if(right = = =true){ $res =node; -Isfound =true; -                 return []; the}Else if(Right.length = = 1){ -Candidates =Right ;Wuyi             } the         } -          Wu         if(!isfound) { - Candidates.push (node.val); About             varCurr =Compareval (candidates); $             if(Curr = = =true){ -res =node; -Isfound =true; -                 return []; A             } +             returnCurr; the         } -          $     } the     functionCompareval (A, b) { the         if(typeofA = = = "Object"){ the             if(A.length = = 2){ theb = a[1]; -A = A[0]; in}Else if(A.length = = 1){ theA = A[0]; the             } About         } the         varIndex1 =Target.indexof (a); the         varIndex2 =Target.indexof (b); the         if(Index1!==-1 && index2!==-1 && (index1!== Index2 | | a = = =b)) { +             return true; -}Else{ the             if(Index1!==-1){Bayi                 return[a]; the}Else if(Index2!==-1){ the                 return[b]; -             } -         } the         return []; the     } the};

[Leetcode] [JavaScript] Lowest Common Ancestor of a Binary Tree