/* * 队列的实现 */ module.exports = function Queue() { this.dataStore = []; this.enqueue = enqueue; this.dequeue = dequeue; this.front = front; this.back = back; this.toString = toString; this.empty = empty; this.count = count; this.has = has; } // 向队尾添加一个元素 function enqueue(element) { this.dataStore.push(element); } // 删除队首的一个元素 function dequeue() { return this.dataStore.shift(); } // 读取队首和队尾的元素 function front() { return this.dataStore[0]; } function back() { if(this.dataStore.length === 0) return; return this.dataStore[this.dataStore.length - 1]; } // 输出队列内所有的元素 function toString() { var retStr = ""; for(var i = 0; i < this.dataStore.length; i++) { retStr += this.dataStore[i] + "\n"; } return retStr; } // 判断队列是否为空 function empty() { if(this.dataStore.length === 0) { return true; } else { return false; } } // 显示队列元素的个数 function count() { return this.dataStore.length; } // 判断当前队列是否有element元素 function has(element) { return this.dataStore.indexOf(element); }