LeetCode | 965. Single value binary tree

LeetCode | 965. Single value binary tree

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• First, determine whether the tree is empty. If it is empty, it will be true directly.
• Then determine whether the val of the left subtree is different from the val of the root.
• Then determine whether the val of the right subtree is different from the val of the root.
• Finally recurse the left subtree and right subtree

bool isUnivalTree(struct TreeNode* root) {
    
    
    if(root == NULL)
        return true;
    
    if(root->left && root->left->val != root->val)
        return false;
    if(root->right && root->right->val != root->val)
        return false;
    
    return isUnivalTree(root->left) && isUnivalTree(root->right);
}