单链表的插入算法

单链表上的基础操作之插入算法，请将函数int InsertElem( LinkList *head, int i, ElemType e)，其中i为要插入元素的位序，插入位序的合法范围为1-6，e为要插入元素，函数返回值为操作成功（OK）与否（ERROR）

#include <stdio.h>

#include <stdlib.h>

#define ERROR 0

#define OK 1

#define N 5

typedef int ElemType;



typedef struct node {

ElemType data;

struct node *next;

} LinkList;



LinkList *InitList() {

LinkList *head;

head = ( LinkList *)malloc( sizeof(LinkList));

head->next = NULL;

return head;

}



LinkList *CreateList(int n) {

int i;

LinkList *head, *p, *r;

head = ( LinkList *)malloc(sizeof(LinkList));

r = head;



for ( i = 1; i <= n; i++) {



p = ( LinkList *)malloc( sizeof( LinkList));

scanf("%d", &( p->data));

r->next = p;

r = p;

}



r->next = NULL;

return head;

}



void PrintLinkList(LinkList *head) {

LinkList *p;

p = head->next;

while ( p != NULL) {

printf("%d,", p->data);

p = p->next;

}

}



int InsertElem( LinkList *head, int i, ElemType e) {

int j=0;

LinkList *p,*q;

p=head;

if(i<1||i>6){

return ERROR;

}

while(j<i-1&&p!=NULL){

p=p->next;

j++;

}

if(p==NULL){

return ERROR;

}

q= ( LinkList *)malloc( sizeof( LinkList));

q->next=p->next;

q->data=e;

p->next=q;

return OK;

}



int main() {

LinkList *head;

int i;

ElemType e;

head = CreateList(N);

scanf("%d %d", &i, &e);

if (!InsertElem( head, i, e))

printf("Failed!\n");

else 

printf("Success!\n");

PrintLinkList(head);

}