32 lines
891 B
JavaScript
32 lines
891 B
JavaScript
// https://www.freecodecamp.org/learn/coding-interview-prep/data-structures/check-if-tree-is-binary-search-tree
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var displayTree = (tree) => console.log(JSON.stringify(tree, null, 2));
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function Node(value) {
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this.value = value;
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this.left = null;
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this.right = null;
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}
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function BinarySearchTree() {
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this.root = null;
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}
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function isBinarySearchTree(tree) {
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// Only change code below this line
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if (tree.root === null) return true;
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const stack = [tree.root];
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while (stack.length) {
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const node = stack.pop();
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const leftChild = node.left;
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if (leftChild !== null) {
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stack.push(leftChild);
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if (node.value <= leftChild.value) return false;
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}
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const rightChild = node.right;
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if (rightChild !== null) {
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stack.push(rightChild);
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if (node.value > rightChild.value) return false;
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}
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}
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return true;
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// Only change code above this line
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}
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