113. Path Sum II

/* 
Dfs recursive with mutable slate
*/
var pathSum = function (root, sum) {
	// recursive dfs helper
	function recurse(node, slate, target) {
		target -= node.val

		if (!node.left && !node.right) {
			if (target === 0) {
				slate.push(node.val)
				res.push(slate.slice(0))
				slate.pop()
			}
			return
		}

		slate.push(node.val)

		if (node.left) recurse(node.left, slate, target)
		if (node.right) recurse(node.right, slate, target)

		slate.pop()
	}

	// overall
	if (!root) return []
	const res = []

	recurse(root, [], sum)
	return res
}