算法

快速排序

var arr = [90,9,12,6,30,60,36,32,40];
    function quickSort(arr){
        if(arr.length<=1){
            return arr
        }
        var l=Math.floor(arr.length/2)
        var lo =arr.splice(l,1)[0]
        var left=[]
        var right=[]
        for (var i=0;i<arr.length;i++){
            if(arr[i]<=lo){left.push(arr[i])}
            else{
                right.push(arr[i])
            }
        }
        return quickSort(left).concat([lo],quickSort(right))
    }

   console.log(quickSort(arr))