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.

利用递归判断

class Solution

 {
public:
    bool isSameTree(TreeNode* p, TreeNode* q)

       {

            if(p==NULL&&q==NULL)

            return true;

            if(p==NULL&&q!=NULL)

            return  false;

            if(p!=NULL&&q==NULL)

            return false;

            if(p!=NULL&&q!=NULL&&p->val!=q->val)

            return false;

            if(p!=NULL&&q!=NULL&&p->val==q->val)

             return (isSameTree(p->right,q->right))&&(isSameTree(p->left,q->left));

          

        }

}；