//定義隊(duì)列

function Queue(){
 this.dataStore = [];
 this.enqueue = enqueue;  //入隊(duì)
 this.dequeue = dequeue;  //出隊(duì)
 this.front = front;   //查看隊(duì)首元素
 this.back = back;   //查看隊(duì)尾元素
 this.toString = toString; //顯示隊(duì)列所有元素
 this.clear = clear;   //清空當(dāng)前隊(duì)列
 this.empty = empty;   //判斷當(dāng)前隊(duì)列是否為空
}

//向隊(duì)列末尾添加一個(gè)元素，直接調(diào)用 push 方法即可

function enqueue ( element ) {
 this.dataStore.push( element );
}

//刪除隊(duì)列首的元素，可以利用 JS 數(shù)組中的 shift 方法

function dequeue () {
 if( this.empty() ) return 'This queue is empty';
 else this.dataStore.shift();
}

//我們通過(guò)判斷 dataStore 的長(zhǎng)度就可知道隊(duì)列是否為空

function empty(){
 if( this.dataStore.length == 0 ) return true;
 else return false;
}

var queue = new Queue();

console.log( queue.empty() );  //true

//添加幾個(gè)元素
queue.enqueue('Apple');
queue.enqueue('Banana');
queue.enqueue('Pear');

console.log( queue.empty() );  // false

//查看隊(duì)首元素，直接返回?cái)?shù)組首個(gè)元素即可

function front(){
 if( this.empty() ) return 'This queue is empty';
 else return this.dataStore[0]；
}

//查看隊(duì)首元素，直接返回?cái)?shù)組最后一個(gè)元素即可

//讀取隊(duì)列尾的元素
function back () {
 if( this.empty() ) return 'This queue is empty';
 else return this.dataStore[ this.dataStore.length - 1 ];
}

//查看隊(duì)首元素
console.log( queue.front() ); // Apple
//查看隊(duì)尾元素 
console.log( queue.back() ); // Pear

//出隊(duì)
queue.dequeue();

//查看隊(duì)首元素
console.log( queue.front() ); // Banana
//查看隊(duì)尾元素 
console.log( queue.back() ); // Pear

//查看對(duì)了所有元素，我這里采用數(shù)組的 join 方法實(shí)現(xiàn)

function toString(){
 return this.dataStore.join('\n');
}

console.log( queue.toString() )  // Apple
         // Banana
         // Pear

//清空當(dāng)前隊(duì)列，也很簡(jiǎn)單，我們直接將 dataStore 數(shù)值清空即可

function clear(){
 delete this.dataStore;
 this.dataStor = [];
}

//清空隊(duì)列

queue.clear();

console.log( queue.empty() ); // true

//基數(shù)排序

var queues = []; //定義隊(duì)列數(shù)組
var nums = [];  //定義數(shù)字?jǐn)?shù)組

//選十個(gè)0~99的隨機(jī)數(shù)進(jìn)行排序
for ( var i = 0 ; i < 10 ; i ++ ){
 queues[i] = new Queue();
 nums[i] = Math.floor( Math.random() * 101 );
}

//排序之前
console.log( 'before radix sort: ' + nums );

//基數(shù)排序
distribution( nums , queues , 10 , 1 );
collect( queues , nums );
distribution( nums , queues , 10 , 10 );
collect( queues , nums );

//排序之后
console.info('after radix sort: ' + nums );

//根據(jù)相應(yīng)的（個(gè)位和十位）數(shù)值，將數(shù)字分配到相應(yīng)隊(duì)列

function distribution ( nums , queues , n , digit ) { //digit表示個(gè)位或者十位的值
 for( var i = 0 ; i < n ; i++ ){
  if( digit == 1){
   queues[ nums[i] % 10 ].enqueue( nums[i] );
  }else{
   queues[ Math.floor( nums[i] / 10 ) ].enqueue( nums[i] );
  }
 }
}

//從隊(duì)列中收集數(shù)字

function collect ( queues , nums ) {
 var i = 0;
 for ( var digit = 0 ; digit < 10 ; digit ++ ){
  while ( !queues[digit].empty() ){
   nums[ i++ ] = queues[digit].front();
   queues[digit].dequeue();
  }
 }
}

//第一組測(cè)試

before radix sort: 23,39,2,67,90,41,47,21,98,13
after radix sort: 2,13,21,23,39,41,47,67,90,98

//第二組測(cè)試

before radix sort: 29,62,38,16,55,26,33,54,76,65
after radix sort: 16,26,29,33,38,54,55,62,65,76