题解 | #合并两个排序的链表#

package main
import . "nc_tools"
/*
 * type ListNode struct{
 *   Val int
 *   Next *ListNode
 * }
 */

/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 *
 * 
 * @param pHead1 ListNode类 
 * @param pHead2 ListNode类 
 * @return ListNode类
*/
func Merge( pHead1 *ListNode ,  pHead2 *ListNode ) *ListNode {
    
    if pHead1 == nil {
        return pHead2
    }

    if pHead2 == nil {
        return pHead1
    }

    if pHead1.Val < pHead2.Val {
        pHead1.Next = Merge(pHead1.Next,pHead2)
        return pHead1
    }else {
        pHead2.Next = Merge(pHead1,pHead2.Next)
        return pHead2
    }

}


func Merge( pHead1 *ListNode ,  pHead2 *ListNode ) *ListNode {
    
    if pHead1 == nil {
        return pHead2
    }
    if pHead2 == nil {
        return pHead1
    }
    vh := &ListNode{}
    cur := vh
    for i := 0;;i++ {
        if (pHead1 == nil || pHead2 == nil) {
            break
        }
        if pHead1.Val < pHead2.Val {
            cur.Next = pHead1
            pHead1 = pHead1.Next
        }else {
            cur.Next = pHead2
            pHead2 = pHead2.Next
        }
        cur = cur.Next
    }

    if pHead1 != nil {
        cur.Next = pHead1
    }

    if pHead2 != nil {
        cur.Next = pHead2
    }
    return vh.Next
}