Discussion on Binary Search Tree : Lowest Common Ancestor Challenge

9 years ago+ 0 comments

Hmm I never thought to use a value test. I used a recursive inTree() function to test if a value was in a particular subtree. The running times of all test cases was 0 so the recursion didn't hurt in this case.

https://www.hackerrank.com/challenges/binary-search-tree-lowest-common-ancestor/submissions/code/25912799

bool inTree(node *head, int value) {
    if (head == NULL) {
        return false;
    } else if (value == head->data) {
        return true;
    } else {
        return inTree(head->left, value) || inTree(head->right, value);
    }
}

node * lca(node * root, int v1,int v2)
{
    if (inTree(root->left, v1) && inTree(root->left, v2)) {
        return lca(root->left, v1, v2);
    } else if (inTree(root->right, v1) && inTree(root->right, v2)) {
        return lca(root->right, v1, v2);
    } else {
        return root;
    }
}

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