javascript算法-单链表

链表相比数组更具灵活性和扩展性。主要有节点数据以及指向节点的指针所构成。

链表中节点的实现【元素和指针】：

let Node = function( element ){
this.element = element;
this.next = null;
};

单链表的实现：

function LinkedList(){
let Node = function( element ){
this.element = element;
this.next = null;
};

let head = null;
let length = 0;

this.append = function( element ){
let newNode = new Node( element );
let current = null;
if( head == null ){
head = newNode;
}else{
current = head;
while( current.next ) {
current = current.next;
}
current.next = newNode;
}
length++;
};

this.size = function(){
return length;
};

this.removeAt = function( pos ){
if( pos > -1 && pos < length ){
var current = head,
index = 0,
prev = null;

if( pos == 0 ){
head = current.next;
}else{
while( index++ < pos ){
prev = current;
current = current.next;
}
prev.next = current.next;
length--;
return current.element;
}
}else{
return null;
}
};

this.print = function(){
let current = head;
while( current ){
console.log( current.element );
current = current.next;
}
};

this.insert = function( pos, element ){
let newNode = new Node( element );
let current, prev, index = 0;
current = head;
if( pos >= 0 && pos <= length ){
if( pos == 0 ){
newNode.next = head;
head = newNode;
}else{
while( index++ < pos ){
prev = current;
current = current.next;
}
newNode.next = current;
prev.next = newNode;
}
length++;
return true;
}else {
return false;
}
};
this.toString = function(){
let current = head, string = '';
while( current ){
string += current.element + ',';
current = current.next;
}
return string.substring( 0, string.length - 1 );
};
this.indexOf = function( element ){
let current = head, index = -1;
while( current ){
index++;
if( current.element == element ){
return index;
}
current = current.next;
}
return -1;
};
this.remove = function( element ){
let pos = this.indexOf( element );
return this.removeAt( pos );
};
this.isEmpty = function(){
return length == 0;
};
this.getHead = function(){
return head;
}
}

var oLink = new LinkedList();
oLink.append( "java" );
oLink.append( "php" );
oLink.append( "javascript" );
oLink.append( "python" );

oLink.print();
console.log( "-----------------------节点个数------------------------")
console.log( oLink.size() );

console.log( "-----------------------删除第2个元素之前------------------------")
console.log( oLink.removeAt( 2 ) );
console.log( "-----------------------删除第2个元素之后------------------------")
oLink.print();
console.log( "节点个数");
console.log( oLink.size() );
console.log( "-----------------------插入节点前------------------------")
oLink.insert( 0, "c语言" );
oLink.insert( 3, "c++语言" );
console.log( "-----------------------插入节点后------------------------")
oLink.print();
oLink.insert( 4, "erlang语言" );
console.log( "-----------------------插入节点后------------------------")
oLink.print();
console.log( "-----------------------节点个数------------------------")
console.log( oLink.size() );

console.log( "-----------------------toString------------------------")
console.log( oLink.toString() );
console.log( "------------------------indexOf-----------------------" );
console.log( oLink.indexOf( "c语言2" ) );
console.log( "------------------------clear-----------------------" );
oLink.print();