LEETCODE 101
you will traverse tree in downward direction.
first check if tree is NULL if it is NULL then return true
Calculate its left & right subtree if
1.one of them is null & other is not then return false 2.both are null then return true 3.if value of (left.left == right.right)&&(left->right == right->left) then go for each left & right subtrees recursively.
CODE ->
int check(struct TreeNode* left,struct TreeNode* right){
if(!left || !right){
return (left == right);
}
if(left->val != right->val){
return 0;
}
return check(left->left,right->right)&&check(left->right,right->left);
}
bool isSymmetric(struct TreeNode* root){
if(root == NULL){
return 1;
}
return check(root->left,root->right);
}