2807.在链表中插入最大公约数

/*
 * @lc app=leetcode.cn id=2807 lang=typescript
 *
 * [2807] 在链表中插入最大公约数
 */

// @lc code=start
/**
 * Definition for singly-linked list.
 * class ListNode {
 *     val: number
 *     next: ListNode | null
 *     constructor(val?: number, next?: ListNode | null) {
 *         this.val = (val===undefined ? 0 : val)
 *         this.next = (next===undefined ? null : next)
 *     }
 * }
 */

function insertGreatestCommonDivisors(head: ListNode | null): ListNode | null {
	if (head == null) return null;
	let current: ListNode | null = head; // 遍历用

	let p = head; // 记录前节点
	while (current) {
		let n = p.next;
		if (n != null) {
			// 下一节点存在时，计算最大公约数
			let valNode = new ListNode(greatestCommonDivisor(p.val, n.val));
			p.next = valNode;
			valNode.next = n;


			p = n
		}
		current = current.next;
	}

	return head;
}

// 求最大公约数
function greatestCommonDivisor(a: number, b: number): number {
	while (b !== 0) {
		let temp = b;
		b = a % b;
		a = temp;
	}
	return a;
}

class ListNode {
	val: number;
	next: ListNode | null;
	constructor(val?: number, next?: ListNode | null) {
		this.val = val === undefined ? 0 : val;
		this.next = next === undefined ? null : next;
	}
}

let listTag1 = new ListNode(1);
let listTag2 = new ListNode(3);
let listTag3 = new ListNode(4);
let listTag4 = new ListNode(7);
let listTag5 = new ListNode(1);
let listTag6 = new ListNode(2);
let listTag7 = new ListNode(6);

listTag1.next = listTag2;
listTag2.next = listTag3;
listTag3.next = listTag4;
listTag4.next = listTag5;
listTag5.next = listTag6;
listTag6.next = listTag7;

console.log(insertGreatestCommonDivisors(listTag1));

// @lc code=end