bool mirrorTree(TreeNode *t1, TreeNode *t2){
if(t1 == NULL && t2 == NULL)
return true;
if((t1 == NULL && t2 != NULL) || (t1 != NULL && t2 == NULL))
return false;
return (t1->val == t2->val) && mirrorTree(t1->left , t2->right) && mirrorTree(t1->right, t2->left);
}
TreeNode *mirrorTree(TreeNode *root) {
if (!root) return 0;
TreeNode *left = root->left;
root->left = mirrorTree(root->right);
root->right = mirrorTree(left);
return root;
}
void mirrorTree(pnode *root) {
pnode temp;
if (*root == NULL) return;
if ((*root)->left == NULL && (*root)->right == NULL) return;
mirrorTree(&((*root)->left));
mirrorTree(&((*root)->right));
temp = (*root)->left;
(*root)->left = (*root)->right;
(*root)->right= temp;
return;
}
// to mirror a tree, we mirror the left and right child recursively.
bool mirrorTree(BTreeNode *tree) {
if(NULL == tree) return true;
// exchange the left and right subtree.
BTreeNode *tmpNode = tree->left;
tree->left = tree->right;
tree->right = tmpNode;
// mirror recursively the subtrees.
mirrorTree(tree->left);
mirrorTree(tree->right);
return true;
}
bool isSymmetric(TreeNode *root) {
// Start typing your C/C++ solution below
// DO NOT write int main() function
if(root == NULL)
return true;
return mirrorTree(root->left, root->right);
}