笔试题小练2（链表）

1、

/*编写代码，移除未排序链表中的重复结点*/#include <stdio.h>#include <string.h>#include <stdlib.h>typedef struct node{int data;struct node *next;}Link;typedef Link* linken;linken head;void insert_tail(int num){linken p = head;while(p->next != NULL){p = p->next;}linken new = (linken)malloc(sizeof(Link));new->data = num;p->next = new;new->next = NULL;}void display(){linken p = head;while(p->next != NULL){p = p->next;printf("%d ",p->data);}printf("\n");}void delete(){linken p = head;linken pre = head;linken ptr = head;while(p->next != NULL){p = p->next;pre = p;while(pre->next != NULL){ptr = pre;pre = pre->next;if(pre->data == p->data){ptr->next = pre->next;}}}}int main(){int i = 0;head = (linken)malloc(sizeof(Link));if(head == NULL){perror("malloc");return 0;}for(i = 0;i < 10;i++){insert_tail(i+1);}insert_tail(5);insert_tail(6);display();delete();display();return 0;}

2、

/*实现一个算法，找出单链表中的倒数第k个结点*/#include <stdio.h>#include <string.h>#include <stdlib.h>typedef struct node{int data;struct node *next;}Link;typedef Link* linken;linken head;void insert_tail(int num){linken p = head;while(p->next != NULL){p = p->next;}linken new = (linken)malloc(sizeof(Link));new->data = num;p->next = new;new->next = NULL;}int display(){linken p = head;int count = 0;while(p->next != NULL){p = p->next;printf("%d ",p->data);count++;}printf("\ncount = %d\n",count);return count;}void search(int count,int k){linken p = head;int m_count = 0;int flag = 0;while(p->next != NULL){p = p->next;m_count++;if(m_count == count-k+1){printf("倒数第%d个结点为：%d\n",k,p->data);flag = 1;break;}}if(flag == 0){printf("超出查找范围！\n");}}int main(){int i = 0;int count = 0;int k = 0;head = (linken)malloc(sizeof(Link));if(head == NULL){perror("malloc");return 0;}for(i = 0;i < 10;i++){insert_tail(i+1);}insert_tail(5);insert_tail(6);count = display();printf("请输入k的值：");scanf("%d",&k);search(count,k);return 0;}

3、

/*编写代码：以给定x为基准，将链表分割成两部分，所有小于x的结点排在大于或等于x的结点之前*/#include <stdio.h>#include <string.h>#include <stdlib.h>typedef struct node{int data;struct node *next;}Link;typedef Link* linken;linken head;void insert_tail(int num)                                                     //尾插{linken p = head;while(p->next != NULL){p = p->next;}linken new = (linken)malloc(sizeof(Link));new->data = num;p->next = new;new->next = NULL;}void display()                                                                 //输出链表{linken p = head;while(p->next != NULL){p = p->next;printf("%d ",p->data);}printf("\n");}void reserve(int num)                                                         //将链表分为两半{linken p = head;linken pre = head;linken temp = NULL;if(p->next == NULL){printf("no data!\n");}while(p->next != NULL)     {pre = p;p = p->next;if(p->data < num)                                                      //如果数字小于所输入的num值{temp = (linken)malloc(sizeof(Link));temp->data = p->data;                                              //将数值取出放入新的结点temp里temp->next = head->next;                                           //然后用temp进行头插head->next = temp;if(p->next == NULL){pre->next = NULL;}pre->next = p->next;                                              //删除原来的结点p = pre;                                                          //重新指向原来的结点}}}int main(){int i = 0;int num = 0;head = (linken)malloc(sizeof(Link));if(head == NULL){perror("malloc");return 0;}insert_tail(6);for(i = 0;i < 10;i++){insert_tail(i+1);}insert_tail(5);insert_tail(6);display();printf("请输入数字：");scanf("%d",&num);reserve(num);display();return 0;}