数据结构day1-3 优先级队列

一、实现代码

    function PriorityQueue() {
      //可以理解为内部类
      function QueueElement(element,priority) {
        this.element = element;
        this.priority = priority;
      }

      // 属性
      this.items = []
      // 方法

      // 将元素加入队列
      PriorityQueue.prototype.enqueue = function(element,priority) {
        
        var queueElement = new QueueElement(element,priority)
        //判断队列是否为空
        if (this.items.length == 0) {
          this.items.push(queueElement)
        } else {
          var added = false
          for (var i=0; i<this.items.length; i++) {
            if(queueElement.priority < this.items[i].priority) {
              this.items.splice(i,0,queueElement)
              added = true
              break
            }
          }
          if(!added) {
            this.items.push(queueElement)
          }
        }
      }
      // 删除前端元素
      PriorityQueue.prototype.dequeue = function() {
        return this.items.shift()
      }
      // 查看前端元素
      PriorityQueue.prototype.front = function() {
        return this.items[0]
      }
      // 查看队列是否为空
      PriorityQueue.prototype.isEmpty = function() {
        return this.items.length == 0
      }
      // 查看队列中元素个数
      PriorityQueue.prototype.size = function() {
        return this.items.length
      }
      // toString 方法
      PriorityQueue.prototype.toString = function() {
        var resultString = ''
        for (var i=0; i< this.items.length; i++) {
          resultString += this.items[i].element + '-' + this.items[i].priority + ' '
        }
        return resultString
      }
    }

    var pq = new PriorityQueue()
    pq.enqueue('abc',111)
    pq.enqueue('cba',200)
    pq.enqueue('nba',50)
    pq.enqueue('nba',66)
    alert(pq)