Same Tree

Description:

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.

Code:

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

      deque<TreeNode*>mP;

      deque<TreeNode*>mQ;

      

      if (p==NULL && q==NULL)

        return true;

    

      if ((p==NULL || q==NULL))

        return false;

        

      mP.push_back(p);

      mQ.push_back(q);

      while (!mP.empty() && !mQ.empty())

      {

          TreeNode* temp_P = mP.front();

          TreeNode* temp_Q = mQ.front();

          

          mP.pop_front();

          mQ.pop_front();

            

          if ( (temp_P->val != temp_Q->val)

          || (temp_P->left == NULL || temp_Q->left == NULL) && (temp_P->left != temp_Q->left)

          || (temp_P->right == NULL || temp_Q->right == NULL) && (temp_P->right != temp_Q->right))

            return false;

            

          if (temp_P->left && temp_Q->left)

          {

            mP.push_back(temp_P->left);

            mQ.push_back(temp_Q->left);

          }

          if (temp_P->right && temp_Q->right)

          {

            mP.push_back(temp_P->right);

            mQ.push_back(temp_Q->right);

          }

   

      }

      if (mP.empty() && mQ.empty())

        return true;

      else

        return false;

    }