快排
const quickSort = arr =>{
let length = arr.length
if(length<=1){return arr;}
let pivotIndex = Math.floor.call(arr,length/2)
let pivot = arr.splice.call(arr,pivotIndex,1)[0]
const left = []
const right = []
for(let i=0;i<length;i++){
if(arr[i]<pivot){
left.push(arr[i])
}else{
right.push(arr[i])
}
}
return quickSort(left).concat([pivot],quickSort(right))
}
归并
const merge = (a,b) =>{
if(a.length===0){return b};
if(b.length===0){return a};
if(a[0]>b[0]){return [b[0]].concat(merge(a,b.slice(1)))}
return [a[0]].concat(merge(a.slice.call(a,1),b))
}
const mergeSort = arr =>{
if(arr.length===1){return arr}
let pivot = Math.floor.call(arr,arr.length/2)
let left = arr.slice.call(arr,0,pivot)
let right = arr.slice.call(arr,pivot)
return merge(mergeSort(left),mergeSort(right))
}