JavaScript 数据结构（5）：单链表 LinkList

/**
* 单链表(LinkList)
*/

/* Link 链表节点 */
function Link (data) {
this.data = data;
this.next = null;
}

Link.prototype.displayLink = function(){
console.log(this.data);
};

/* LinkList 单链表 */
function LinkList () {
var first = null,       // 链表中的第一个链结点
size = 0;

return {
isEmpty: function(){        // 判断链表是否为空
return first === null;
},
insertFirst: function(data){        // 在表头插入一个结点
var link = new Link(data);
link.next = first;
first = link;
size++;
},
deleteFirst: function(){        // 删除表头结点
if(first !== null){
var link = first;
first = first.next;
size--;
return link;
}
return null;
},
search: function(key){      // 根据指定值查找结点
var current = first;

while(current !== null){
if(current.data === key){
console.log('Find it!');
return current;
}
current = current.next;
}
console.log('Can not find such a Link.');
return null;
},
delete: function(key){      // 根据指定值删除结点
var previous = null,
current = first;

while(current !== null){
if(current.data === key){
size--;

console.log('Find and delete it!');
if(current === first){
first = current.next;
return current;
}else{
previous.next = current.next;
return current;
}
}

previous = current;
current = current.next;
}
console.log('Can not delete such a Link.');
return null;
},
displayList: function(){        // 显示整个链表
console.log('List(first --> last):')
var current = first;
while(current !== null){
current.displayLink();
current = current.next;
}
},
size: function(){
return size;
}
}
}

// 测试
var list1 = new LinkList();

console.log('Empty? ' + list1.isEmpty());
console.log('-----------------------');

list1.insertFirst(1);
list1.insertFirst(2);
list1.insertFirst(3);
list1.displayList();
console.log('-----------------------');

list1.deleteFirst();
list1.displayList();
console.log('-----------------------');

console.log('search 3: %o', list1.search(3));
console.log('search 2: %o', list1.search(2));
console.log('-----------------------');

console.log('delete 3: %o', list1.delete(3));
console.log('delete 2: %o', list1.delete(2));