JS排序算法
作者：互联网
冒泡排序
<script>
let arr = [3, 5, 6, 10, 2, 1]
//冒泡排序：相邻两个值作比较 将较大的换到后面 将较小的换到前面
//i=0 i<6 arr[0] 3 arr[1] 5 ====>[3,5,6,10,2,1]
//i=1 i<6 arr[1] 5 arr[2] 6 ====>[3,5,6,10,2,1]
//i=2 i<6 arr[2] 6 arr[3] 10===>[3,5,6,10,2,1]
//i=3 i<6 arr[3] 10 arr[4] 2 ====>[3,5,6,2,10,1]
//i=4 i<6 arr[4] 10 arr[5] 1 ===>[3,5,6,2,1,10]
//i=5 i<6 arr[5] 1 arr[6] undefined ====>[3,5,6,2,1,10]
for (let j = 1; j < arr.length; j++){
for(let i = 0; i < arr.length-j; i++){
if (arr[i] > arr[i + 1]){
var middle = arr[i]
arr[i] = arr[i + 1]
arr[i + 1] = middle
}
}
}
</script>
冒泡排序过程
for (let i = 0; i < arr.length - 1; i++){
if (arr[i] > arr[i + 1]) {
var middle = arr[i]
arr[i] = arr[i + 1]
arr[i + 1] = middle
}
}
for (let i = 0; i < arr.length -2; i++){
if (arr[i] > arr[i + 1]) {
var middle = arr[i]
arr[i] = arr[i + 1]
arr[i + 1] = middle
}
}
for (let i = 0; i < arr.length -3; i++){
if (arr[i] > arr[i + 1]) {
var middle = arr[i]
arr[i] = arr[i + 1]
arr[i + 1] = middle
}
}
for (let i = 0; i < arr.length -4; i++){
if (arr[i] > arr[i + 1]) {
var middle = arr[i]
arr[i] = arr[i + 1]
arr[i + 1] = middle
}
}
for (let i = 0; i < arr.length -5; i++){
if (arr[i] > arr[i + 1]) {
var middle = arr[i]
arr[i] = arr[i + 1]
arr[i + 1] = middle
}
}
选择排序
<script>
let arr = [1, 4, 3, 2, 5, 7, 6, 9, 8, 0]
/* minIndex=0
1 i=1 i<10 arr[0] 1 arr[1] 4 minIndex=0
2 i=2 i<10 arr[0] 1 arr[2] 3 minIndex=0
3 i=3 i<10 arr[0] 1 arr[3] 2 minIndex=0
4 i=4 i<10 arr[0] 1 arr[4] 5 minIndex=0
5 i=5 i<10 arr[0] 1 arr[5] 7 minIndex=0
6 i=6 i<10 arr[0] 1 arr[6] 6 minIndex=0
7 i=7 i<10 arr[0] 1 arr[7] 9 minIndex=0
8 i=8 i<10 arr[0] 1 arr[8] 8 minIndex=0
9 i=9 i<10 arr[0] 1 arr[9] 0 minIndex=9 [0,4,3,2,5,7,6,9,8,1]
*/
/* minIndex=1
1 i=2 i<10 arr[1] 4 arr[2] 3 minIndex =2
2 i=3 i<10 arr[2] 3 arr[3] 2 minIndex = 3
3 i=4 i<10 arr[3] 2 arr[4] 5 minIndex =3
4 i=5 i<10 arr[3]2 arr[5] 7 minIndex =3
5 i=6 i<10 arr[3] 2 arr[6] 6 minIndex =3
6 i=7 i<10 arr[3] 2 arr[7] 9 minIndex = 3
7 i=8 i<10 arr[3] 2 arr[8] 8 minIndex =3
8 i=9 i<10 arr[3] 2 arr[9] 1 minIndex = 9[0,1,3,2,5,7,6,9,8,4]
9i=10 i<10 终止
*/
for (let j = 0; j < arr.length - 1; j++) {
let minIndex = j
for (let i = j + 1; i < 10; i++) {
if (arr[i] < arr[minIndex]) {
minIndex = i
}
}
let middle = arr[j]
arr[j] = arr[minIndex]
arr[minIndex] = middle
}
console.log(arr)
</script>
选择排序过程
let arr = [3, 1, 4, 2, 6, 5]
//************************************************************************************
let min_index = 0
for (let i = 1; i < arr.length; i++) {
if (arr[i] < arr[min_index]) {
min_index = i
}
}
var middle = arr[0]
arr[0] = arr[min_index]
arr[min_index] = middle
//************************************************************************************
min_index = 1
for (let i = 2; i < arr.length; i++) {
if (arr[i] < arr[min_index]) {
min_index = i
}
}
var middle = arr[1]
arr[1] = arr[min_index]
arr[min_index] = middle
//************************************************************************************
min_index = 2
for (let i = 3; i < arr.length; i++) {
if (arr[i] < arr[min_index]) {
min_index = i
}
}
var middle = arr[2]
arr[2] = arr[min_index]
arr[min_index] = middle
//************************************************************************************
min_index = 3
for (let i = 4; i < arr.length; i++) {
if (arr[i] < arr[min_index]) {
min_index = i
}
}
var middle = arr[3]
arr[3] = arr[min_index]
arr[min_index] = middle
//************************************************************************************
min_index = 4
for (let i = 5; i < arr.length; i++) {
if (arr[i] < arr[min_index]) {
min_index = i
}
}
var middle = arr[4]
arr[4] = arr[min_index]
arr[min_index] = middle
//************************************************************************************
标签：index,arr,min,++,JS,middle,算法,let,排序 来源： https://www.cnblogs.com/Thantics/p/16573363.html