节流改造函数

题目描述：

实现一个特殊的节流函数，入参：callback, interval, maxCount,效果为在interval的时间内最多执行maxCount次调用

function specialThrottle(fn, interval, maxCount) {
    let num = 0;
    let timeStampArr = [];
    return function () {
        let curr = new Date().getTime();
        if (num < maxCount) {
            fn.call();
            timeStampArr.push(curr);
            num++
        } else {
            timeStampArr.shift();
            if (curr - timeStampArr[0] > interval) {
                fn.call();
                timeStampArr.push(curr);
                num++
            }
        }
    }
}