快速排序

var arr = [8,9,6,1,3,4,5]
        var i = 0;
        function sort(pArr) {
            // console.log(pArr)
            i++
            if (pArr.length <= 1) {
                return pArr
            }
            var left = []
            var right = []
            var k = pArr[0]
            for (var m = 1; m < pArr.length; m++) {
                if(pArr[m] <= k) {
                    left.push(pArr[m])
                } else if(pArr[m] > k) {
                    right.push(pArr[m])
                }
            }
            left = sort(left)
            right = sort(right)
            console.log('left:', left)
            console.log('mid:', k)
            console.log('right:', right)
            return left.concat([k]).concat(right)
        }
        var re = sort(arr)
        console.log(re)