100. Same Tree

Given 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.

/** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */ class Solution { public boolean isSameTree(TreeNode p, TreeNode q) { if(q == null && p == null) return true; if(!checks(p,q)) return false; Queue nodesp = new LinkedList(); nodesp.add(p); Queue nodesq = new LinkedList(); nodesq.add(q); while(!nodesp.isEmpty()){ int n = nodesp.size(); while(n>0){ TreeNode currp = nodesp.poll(); TreeNode currq = nodesq.poll(); if(currq.val != currp.val) return false; if(!checks(currq.right,currp.right)) return false; if(!checks(currq.left,currp.left)) return false; if(currp.left != null){ nodesp.add(currp.left); nodesq.add(currq.left); } if(currp.right != null){ nodesp.add(currp.right); nodesq.add(currq.right); } n--; } } return true; } public boolean checks(TreeNode p, TreeNode q){ if(q == null && p == null) return true; if((q ==null && p != null) || (p ==null && q != null)) return false; int a =p.val; int b = q.val; if(p.val != q.val) return false; return true; } }