这是我参与更文挑战的第3天,活动详情查看: 更文挑战
1、sort排序
// 数组排序
var arr=[3,4,100,9,2,16];
arr.sort(function(a,b){
return b-a; //降序排列,return a-b; ——>升序排列
}) //括号里不写回调函数,则默认按照字母逐位升序排列,结果为[2,3,4,9,16,100]
2、插入排序
var arr=[10,44,82,50,70,74,29,1,40,36,58,21,56,44,43,61,222,48];
for(var i=0;i<arr.length;i++){
var n=i;
while(arr[n]>arr[n+1] && n>=0){
var temp=arr[n];
arr[n]=arr[n+1];
arr[n+1]=temp;
n--;
}
}
3、冒泡排序
//性能一般
var arr=[10,44,82,50,70,74,29,1,40,36,58,21,56,44,43,61,222,48];
//冒泡排序,每一趟找出最大的,总共比较次数为arr.length-1次,每次的比较次数为arr.length-1次,依次递减
var temp;
for(var i=0;i<arr.length-1;i++){
for(var j=0;j<arr.length-1;j++){
if(arr[j]>arr[j+1]){
temp=arr[j];
arr[j]=arr[j+1];
arr[j+1]=temp;
}
}
}
4、选择排序
//性能一般
var arr=[10,44,82,50,70,74,29,1,40,36,58,21,56,44,43,61,222,48];
var temp;
for(var i=0;i<arr.length-1;i++){
for(var j=i+1;j<arr.length;j++){
if(arr[i]>arr[j]){
temp=arr[i];
arr[i]=arr[j];
arr[j]=temp;
}
}
}
5、桶排序
var arr=[10,44,82,50,70,74,29,1,40,36,58,21,56,44,43,61,222,48];
var arr2=[];
for(var i=0;i<arr.length;i++){
var key=arr[i];
arr2[key]=1;
}
for(var j in arr2){
console.log(j);
}
6、希尔排序
function xier(arr){
var interval = parseInt(arr.length / 2); //分组间隔设置
while(interval > 0){
for(var i = 0 ; i < arr.length ; i ++){
var n = i;
while(arr[n] < arr[n - interval] && n > 0){
var temp = arr[n];
arr[n] = arr[n - interval];
arr[n - interval] = temp;
n = n - interval;
}
}
interval = parseInt(interval / 2);
}
return arr;
}
xier([10,44,82,50,70,74,29,1,40,36,58,21,56,44,43,61,222,48]);
7、快速排序
function quickSort(arr){
if(arr.length <= 1){
return arr;
}
var left = [];
var right = [];
var midIndex = parseInt(arr.length / 2);
var mid = arr[midIndex];
for(var i = 0 ; i < arr.length ; i++){
if(i == midIndex) continue;
if( arr[i] < mid){
left.push(arr[i])
}else{
right.push(arr[i]);
}
}
return quickSort(left).concat([mid],quickSort(right));
}
[1,2].concat([3],[4,5]); //[1, 2, 3, 4, 5]