冒泡排序和快速排序

冒泡排序：比较次数（n+1）*n/2，时间复杂度为O(n²)

function bubblesort(arr){
    var temp;
    for(var i=0;i<arr.length-1;i++){
        for(var j = arr.length-1;j>i;j--){
            if(arr[j-1]>arr[j]){
                temp = arr[j-1];
                arr[j-1] = arr[j];
                arr[j]=temp;
            }
        }
    }
}
            
var arr = [51,33,62,96,87,17,28,51];
            
bubblesort(arr);

快速排序时间复杂度为O(nlog₂n)

function partition(arr,left,right){
    var baseNum = arr[left];
    while(left<right){
        while(left<right&& arr[right]>=baseNum){
            right = right -1;
                        
        }
        arr[left] = arr[right];
        while(left<right && arr[left]<=baseNum){
            left = left + 1;
        }
        arr[right] = arr[left];
    }
    arr[left] = baseNum;
    return left;
}
            
function quicksort(arr,left,right){
    if(left<right){
        var i = partition(arr, left, right);
        quicksort(arr, left, i - 1);
        quicksort(arr, i + 1, right);
    }
}
            
var arr = [51,33,62,96,87,17,28,51];
            
quicksort(arr);