/*

* main.c

*  链表

*  Created on: Oct 29, 2010

*      Author: jenson

*/

#include

#include

struct chain {

int value;

struct chain *next;

};

struct chain *create();

struct chain * insert(struct chain *head, int a, int b);

struct chain * delete(struct chain *head, int a);

void display(struct chain * head);

int main() {

struct chain *q, *head;

int a, b;

q = create();

head = q;

display(q);

printf("\n请输入的表元素数据位于哪个数据之前:");

scanf("%d", &a);

printf("\n请输入所要插入的数据：");

scanf("%d", &b);

q = insert(head, a, b);

display(q);

printf("\n请输入所要删除的数据：");

scanf("%d", &b);

head = q;

q = delete(head, b);

display(q);

free(q);

return 0;

}

struct chain * create() {

struct chain * head, *tail, *p;

int x;

head = tail = NULL;

int i = 0;

for (i = 0; i < 4; i++) {

printf("insert data %d:", i);

scanf("%d", &x);

p = (struct chain *) malloc(sizeof(struct chain));

if (p == NULL) {

perror("malloc");

exit(1);

}

p->value = x;

p->next = NULL;

if (head == NULL) {

head = tail = p;

} else {

tail = tail->next = p;

}

}

return head;

}

struct chain * insert(struct chain *head, int a, int b) {

struct chain *p, *q, *s;

s = (struct chain *) malloc(sizeof(struct chain));

if (s == NULL) {

perror("insert create");

exit(1);

}

s->value = b;

if (head == NULL) {

head = s;

s->next = head;

}

if (head->value == a) {

s->next = head;

head = s;

} else {

p = head;

while ((p->value != a) && (p->next != NULL)) {

q = p;

p = p->next;

}

if (p->value == a) {

q->next = s;

s->next = p;

} else {//插入节点s作为表尾

p->next = s;

s->next = NULL;

}

}

return head;

}

struct chain * delete(struct chain *head, int a) {

struct chain *p, *q;

if (head == NULL) {

perror("空链表,退出\n");

exit(1);

} else if (head->value == a) {//第一个节点为a节点

p = head;

head = p->next;

} else {

p = head;

while (p->value != a && p->next != NULL) {

q = p;

p = p->next;

}

if (p->value != a) {

printf("没有找到节点%d\n", a);

} else {

q->next = p->next;

free(p);

}

}

return head;

}

void display(struct chain * head) {

if (head != NULL) {

struct chain * p;

p = head;

while (p != NULL) {

printf("%d\t", p->value);

p = p->next;

}

}

}