链表常见操作练习

链表是一个很重要的数据结构，一直没有好好的写过练习，这次放假，

好好练习一下。

1、定义链表节点

#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
typedef struct Int_Node {
    int data; //数据
    struct Int_Node * next; //指向下一个节点
}Node;

2、合并两个有序链表

//版本1

Node* Merge(Node *p, Node *q){
    Node *head, *tmp;
    assert(p && q);
    if(p->data <= q->data){
        head = tmp = p;
        p = p->next;
    }else{
        head = tmp = q;
        q = q->next;
    }
    while(p && q){
        if(p->data <= q->data){
            tmp->next = p;
            tmp = p;
            p = p->next;
        }else{
            tmp->next = q;
            tmp = q;
            q = q->next;
        }
    }
    if(p){
        tmp->next = p;
    }
    if(q){
        tmp->next = q;
    }
    return head;
}

//版本2

Node* Merge2(Node *p, Node *q){
    Node *head = NULL,
  *tmp = NULL,
  *cur = NULL;
    while(p && q){
        if(p->data <= q->data){
            cur = p;
            p = p->next;
        }else{
            cur = q;
            q = q->next;
        }
        if(NULL == head){
            head = tmp = cur;
        }else{
            tmp->next = cur;
            tmp = cur;
        }
    }
    if(NULL == p){
        tmp->next = q;
    }else{
        tmp->next = p;
    }
    return head;
}