本题要求实现两个函数,分别将读入的数据存储为单链表、将链表中偶数值的结点删除。链表结点定义如下:
struct ListNode {
int data;
struct ListNode *next;
};
函数接口定义:
struct ListNode *createlist();
struct ListNode *deleteeven( struct ListNode *head );
函数createlist
从标准输入读入一系列正整数,按照读入顺序建立单链表。当读到−1时表示输入结束,函数应返回指向单链表头结点的指针。
函数deleteeven
将单链表head
中偶数值的结点删除,返回结果链表的头指针。
裁判测试程序样例:
#include <stdio.h>
#include <stdlib.h>
struct ListNode {
int data;
struct ListNode *next;
};
struct ListNode *createlist();
struct ListNode *deleteeven( struct ListNode *head );
void printlist( struct ListNode *head )
{
struct ListNode *p = head;
while (p) {
printf("%d ", p->data);
p = p->next;
}
printf("\n");
}
int main()
{
struct ListNode *head;
head = createlist();
head = deleteeven(head);
printlist(head);
return 0;
}
/* 你的代码将被嵌在这里 */
输入样例:
1 2 2 3 4 5 6 7 -1
输出样例:
1 3 5 7
struct ListNode *createlist(){
struct ListNode * p ,*head=NULL,*tail;
int size = sizeof (struct ListNode);
int num;
scanf("%d",&num);
while(num!=-1)
{
p=(struct ListNode *) malloc(size);
p->data = num;
if(head==NULL){
head=p;
tail=p;
}
else {
tail->next = p;
}
tail = p;
scanf("%d",&num);
}
p->next=NULL;
return head;
}
struct ListNode *deleteeven( struct ListNode *head ){
struct ListNode * ptr,*ptr1,*ptr2;
while(head && head->data %2 ==0){
ptr1=head;
head = head->next;
free(ptr1);
}
ptr1=head;
while(ptr1 && ptr1 ->next !=NULL)
{
while(ptr1->next && ptr1->next->data%2==0)
{ //直接跳过要删除的那一部分
ptr2=ptr1->next;
ptr1->next=ptr2->next;
}
ptr1=ptr1->next;
}
return head;
}