1171. Remove Zero Sum Consecutive Nodes from Linked List

/**
 * @param {ListNode} head
 * @return {ListNode}
 */

const { ListNode } = require('./utils.js')
// https://leetcode.com/problems/remove-zero-sum-consecutive-nodes-from-linked-list/discuss/366350/C%2B%2B-O(n)-(explained-with-pictures)
var removeZeroSumSublists = function (head) {
	const root = new ListNode(0),
		map = { 0: root }
	let accumulative = 0
	root.next = head

	while (head !== null) {
		accumulative += head.val

		if (map[accumulative]) {
			let prev = map[accumulative],
				start = prev,
				aux = accumulative

			while (prev !== head) {
				prev = prev.next
				aux += prev.val
				if (prev !== head) delete map[aux]
			}

			start.next = head.next
		} else {
			map[accumulative] = head
		}
		head = head.next
	}

	return root.next
}