Leetcode 21.合并两个有序链表 JavaScript (Day 10)

POLITE32026-01-03 17:58

js一刷暴力(but双百)

javascript 复制代码

var mergeTwoLists = function(list1, list2) {
    let p1=null,p2=null,head=null;
    if (!list1) return list2;
    if (!list2) return list1;
    if(list1.val>=list2.val){
        head=list2;
        p2=list1;
        p1=list2;
    }else{
        head=list1;
        p1=list1;
        p2=list2;
    }
    while(p2&&p1.next){
        let cur=p2.next;
        if(p2.val>=p1.val&&p2.val<=p1.next.val){
            let temp=p1.next;
            p1.next=p2;
            p2.next=temp;
            p1=p1.next;
            p2=cur;
        }
        else{
            p1=p1.next;
        }
    }
    if(p1.next===null){
        p1.next=p2;
    }
    return head;
};

js 一刷循环迭代设置哨兵

javascript 复制代码

var mergeTwoLists = function(list1, list2) {
    const dummy=new ListNode();//哨兵
    let cur=dummy;
    while(list1&&list2){
        if(list1.val<=list2.val){
            cur.next=list1;
            list1=list1.next;
        }
        else{
            cur.next=list2;
            list2=list2.next;
        }
        cur=cur.next;
    }
    cur.next=list1??list2; //list不为空返回list1,为空返回list2
    return dummy.next;
};

js一刷递归

javascript 复制代码

var mergeTwoLists = function(list1, list2) {
    if(!list1) return list2;
    if(!list2) return list1;
    if(list1.val<list2.val){
        list1.next=mergeTwoLists(list1.next,list2)
        return list1;
    }
    else{
        list2.next=mergeTwoLists(list2.next,list1)
        return list2;
    }
};