面试题

 /*
 * 实现一个LazyMan，可以按照以下方式调用:
LazyMan(“Hank”)输出:
Hi! This is Hank!
LazyMan(“Hank”).sleep(10).eat(“dinner”)输出
Hi! This is Hank!
//等待10秒..
Wake up after 10
Eat dinner~

LazyMan(“Hank”).eat(“dinner”).eat(“supper”)输出
Hi This is Hank!
Eat dinner~
Eat supper~

LazyMan(“Hank”).sleepFirst(5).eat(“supper”)输出
//等待5秒
Wake up after 5
Hi This is Hank!
Eat supper
以此类推。
 * 
 * 
 * */
class _LazyMan {
    constructor(name) {
        this.tasks = [];
        const task = () => {
            console.log(`Hi! This is ${name}`);
            this.next();
        }
        this.tasks.push(task);
        setTimeout(() => {               // 把 this.next() 放到调用栈清空之后执行
            this.next();
        }, 0);
    }

    next() {
        const task = this.tasks.shift(); // 取第一个任务执行
        task && task();
    }

    sleep(time) {
        this._sleepWrapper(time, false);
        return this;                     // 链式调用
    }

    sleepFirst(time) {
        this._sleepWrapper(time, true);
        return this;
    }

    _sleepWrapper(time, first) {
        const task = () => {
            setTimeout(() => {
                console.log(`Wake up after ${time}`);
                this.next();
            }, time * 1000)
        }
        if (first) {
            this.tasks.unshift(task);     // 放到任务队列顶部
        } else {
            this.tasks.push(task);        // 放到任务队列尾部
        }
    }

    eat(name) {
        const task = () => {
            console.log(`Eat ${name}`);
            this.next();
        }
        this.tasks.push(task);
        return this;
    }
}

function LazyMan(name) {
    return new _LazyMan(name);
}

  let	s = "cbbdsdasssdshhdsgfgshigsadifggfstrgusadsfdgsadfdgiyasgigouasohbsdfpapsadmpnsdsas67rgtraddsadsadssaafasf7474safas"
	var isPalindrome = function(str:string) {
		let left=0,right=str.length-1;
		while(right>=left){
			if(str.charAt(left)!==str.charAt(right)){
				return null;
			}
			left++;
			right--;
		}
		return str;
	}

	function longestPalindrome(s: string): string {
		let left = 0
		let right = 0
		let maxlength = 0
		let maxString = ''
		for (let i =0; i<s.length;i++){
			left = i
			right = s.length - 1
			if(right - left <= maxString.length){
				return maxString
			}
			while (right>left){
				if(s.charAt(right) === s.charAt(left)){
					let str=isPalindrome(s.slice(left,right+1));
					if(str!=null&&str.length>maxString.length){
						maxString=str;
						break
				}
			}
				right--
			}
		}
		return  maxString
	};

	console.log(longestPalindrome(s))