C - 数据结构之 循环链表

#include 

typedef struct node{
	int data;
	struct node * next;
}linklistnode;
typedef struct {
	linklistnode *rear;//头指针
	int length; 
	
}linklist; 


//创建表
linklist * createlist(linklist *);
//初始化表 
linklist * initlist(linklist *); 
//求表长 
int getlength(linklist *);
//插入 
linklist * insertlist(linklist *,int ,int );
//前插
linklist * insertlistatfirst(linklist *,int ); 
//按值删除 
linklist * deletelistbyvalue(linklist *,int );
//按序号删除 
linklist * deletelistbyindex(linklist *,int );
//删除头节点 
linklist * deletefirstnode(linklist *); 
//按值查找 
linklistnode * searchbyvalue(linklist *,int );
//按值查找的节点的前一个节点
linklistnode * searchbyvalue2(linklist *,int ); 
//按序号查找 
linklistnode * searchbyindex(linklist *,int ); 
//按序号查找2 
linklistnode * searchbyindex2(linklist *list,int pos);
//去重
linklistnode * deleterepeatvalue(linklist *,int ); 
linklistnode * deleterepeatvalue2(linklist *,int); 

//创建表函数 
linklist * createlist(linklist *list){
	list = (linklist *)malloc(sizeof(linklist));
	printf("\n创建表成功");
	return list;
}
//初始化表函数 
linklist * initlist(linklist *list){
	if(list == null){
		printf("\n表未创建，请先创建再初始化！");
		return null;
	}
	list->head = null;
	list->rear = null;
	list->length = 0;
	printf("\n初始化表成功");
	return list;
}
//后插函数
linklist * insertlistatlast(linklist *list,int value){
	linklistnode *temp;
	
	if(list == null){
		printf("\n表不存在,请先创建并初始化");
		return null;
	}
	
	temp = (linklistnode *)malloc(sizeof(linklistnode));
	
	if(list->length == 0){
		temp->data = value;
		list->rear = temp;
		temp->next = list->rear;
	}else{
		temp->data = value;
		temp->next = list->rear->next;
		list->rear->next = temp;
		list->rear = temp;
	}
 	list->length++;
	printf("\n插入成功");
	return list;
} 
//随意插入函数
linklist *insertlist(linklist *list,int pos,int value){
	linklistnode *temp = null,*p = null;
	linklistnode *newnode;
	if(list == null){
		printf("\n表不存在,请先创建并初始化");
		return null;
	}
	if( pos < 1 || pos > list->length+1){
		printf("\n插入位置不正确");
		return list;
	}
	if(pos == list->length+1){
		list = insertlistatlast(list,value);
		return list;
	}
	temp = searchbyindex(list,pos);
	if(temp){
		newnode = (linklistnode *)malloc(sizeof(linklistnode));
		newnode->data = value;
		newnode->next = temp->next;
		temp->next = newnode;
		list->length++;
	}
	printf("\n插入成功"); 
	return list;
}
//按序号查找
linklistnode * searchbyindex(linklist *list,int pos){
	if(list == null){
		printf("\n表不存在,请先创建并初始化");
		return null;
	}
	if( pos < 1 || pos > list->length){
		printf("\n查找的位置不正确");
		return null;
	}
	int cnt = 1;
	linklistnode *p;
	p = list->rear;
	while(cnt!=pos){
		p=p->next;
		cnt++;
	}
	return p;
}
//按序号查找2 (返回前一个节点)
linklistnode * searchbyindex2(linklist *list,int pos){
	if(list == null){
		printf("\n表不存在,请先创建并初始化");
		return null;
	}
	if( pos < 1 || pos > list->length){
		printf("\n查找的位置不正确");
		return null;
	}
	int cnt = 0;
	linklistnode *p;
	p = list->rear;
	while(cnt!=pos){
		p=p->next;
		cnt++;
	}
	return p;
}
//输出
void displaylist(linklist *list){
	linklistnode *p;
	if(list == null){
		printf("\n表不存在,请先创建并初始化");
		return ;
	}
	p = list->rear->next;
	int i = 0;
	while(ilength){
		printf("\t%d",p->data);
		p = p->next;
		i++;
	}
	return ;
}
//按值查找 
linklistnode * searchbyvalue(linklist *list,int value){
	linklistnode *p = null;
	if(list == null){
		printf("\n表不存在,请先创建并初始化");
		return null;
	}
	p = list->rear;
	int cnt = 0;
	while(cnt < list->length){
		if(p->data == value){
			return p;
		}else{
			p = p->next;
			cnt++;
		}
	}
	return null;
}
//删除链表第一个节点 
linklist * deletefirstnode(linklist *list){
	linklistnode *p = null,*q = null;
	if(list == null){
		printf("\n表不存在,请先创建并初始化");
		return null;
	}
	q = list->rear->next;
	list->rear->next = q->next;
	free(q);
	list->length--;
	printf("\n删除成功");
	return list; 
}

//按序号删除
linklist * deletelistbyindex(linklist *list,int pos){
	linklistnode *p = null,*q = null;
	if(list == null){
		printf("\n表不存在,请先创建并初始化");
		return null;
	}
	if(pos < 1 || pos > list->length){
		printf("\n删除位置不合法");
		return list; 
	}
	if(pos == 1){
		q = list->rear->next;
		list->rear->next = q->next;
		free(q);
		list->length--;
		printf("\n删除成功");
		return list;
	}
	p = searchbyindex2(list,pos-1);
	if(p != null){
		q = p->next;
		p->next = q->next;
		free(q);
		list->length--; 
		printf("\n删除成功"); 
	}
	return list;
}
//按找值为value的节点的前一个节点 
linklistnode * searchbyvalue2(linklist *list,int value){
	linklistnode *p = null;
	if(list == null){
		printf("\n表不存在,请先创建并初始化");
		return null;
	}
	p = list->rear;
	int cnt = 0;
	while(cntlength){
		if(p->next->data == value){
			return p;
		}else{
			cnt++;
			p = p->next;
		}
	}
	return null;
}
//按值删除
linklist * deletelistbyvalue(linklist *list,int value){
	linklistnode *p = null,*q = null;;
	if(list == null){
		printf("\n表不存在,请先创建并初始化");
		return null;
	}
	p = list->rear;
	if(p->next->data == value){
		list = deletefirstnode(list);
		return list;
	}
	p = searchbyvalue(list,value);
	if(p != null){
		q = p->next;
		p->next = q->next;
		free(q);
		list->length--;
		printf("\n删除成功");
		return list;
	}
	return list;
}
//去重
linklistnode * deleterepeatvalue(linklist *list,int value){
	linklistnode *p = null,*q = null;;
	if(list == null){
		printf("\n表不存在,请先创建并初始化");
		return null;
	}
	p = list->rear->next;
	if(p->data == value){
		list = deletefirstnode(list);
		return list;
	}
	p = searchbyvalue2(list,value);
	if(p != null){
		q = p->next;
		p->next = q->next;
		free(q);
		list->length--;
		return list;
	}
	return list;
}
int main(int argc, char *argv[])
{
	linklistnode *w = null;
	int flag = 1;
	int choice;
	int value;
	int pos;
	linklistnode * tempnode = null;
	linklist * list = null;
	while(1){
		printf("\n------链表---------\n");
		printf("\n------1.创建表-----\n");
		printf("\n------2.初始化-----\n");
		printf("\n------3.求表长-----\n");
		printf("\n------4.尾部插入-------\n");
		printf("\n------5.随意插入-------\n");
		printf("\n------6.按值删除---\n");
		printf("\n------7.按序号删除-\n");
		printf("\n------8.按值查找---\n");
		printf("\n------9.按序号查找-\n");
		printf("\n------10.输出表-----\n");
		printf("\n------11.去重-----\n");
		printf("\n------0.退出-------\n");
		
		printf("\n您的选择是：");
		scanf("%d",&choice);
		
		switch(choice){
			case 1:
				list = createlist(list);
				break;
			case 2:
				list = initlist(list);
				break;
			case 3:
				printf("表长为：%d",list->length);
				break;
			case 4:
				printf("\n请输入要插入的值:");
				scanf("%d",&value);
				list = insertlistatlast(list,value);
				break;
			case 5:
				printf("\n请输入要插入的位置：");
				scanf("%d",&pos);
				printf("\n请输入要插入的值:");
				scanf("%d",&value); 
				list = insertlist(list,pos,value);
				break;
			case 6:
				printf("\n请输入要删除的值：");
				scanf("%d",&value);
				list = deletelistbyvalue(list,value);
				break;
			case 7:
				printf("\n请输入要删除元素的位置:");
				scanf("%d",&pos); 
				list = deletelistbyindex(list,pos);
				break;
			case 8:
				printf("\n请输入要查找的值:");
				scanf("%d",&value);
				tempnode = searchbyvalue(list,value);
				if(tempnode == null){
					printf("\n查找失败");
				}else{
					printf("\n该节点地址：%x",tempnode);
					printf("\n该节点的值：%d",tempnode->data);
				} 
				break;
			case 9:
				printf("\n请输入要查找的位置：");
				scanf("%d",&pos);
				tempnode = searchbyindex2(list,pos);
				if(tempnode == null){
					printf("\n查找不成功");
				}else{
					printf("\n结点的值：%d",tempnode->data);
					printf("\n结点的地址：%x",tempnode);
				}
				break;
			case 10:
				displaylist(list);
				break;
			case 11:
				printf("\n请输入要去重的值：");
				scanf("%d",&value);
				w = searchbyvalue(list,value);
				w->data = value+1;
				while(searchbyvalue(list,value) != null){
					list = deleterepeatvalue(list,value);	
				}
				w->data = value;
				printf("\n去重成功！");
				break; 
			case 0:
				return 0;
				break;
			default:
				printf("\n您的选择有误，请重新选择"); 
		}
	}
	return 0;
}