一、快速排序
function quiker (arr) {
let len = arr.length
let left = [],
right= []
if(len <= 1) return arr
// 原数组中删除一个元素 并返回该元素
let current = arr.splice(Math.floor(len / 2),1)[0]
arr.forEach(item => {
if (current >= item){
left.push(item)
} else {
right.push(item)
}
})
return quiker(left).concat([current],quiker(right))
}