function bubbleSort(arr) {
let n = arr.length;
for (let i = 0; i < n-1 ; i ) {
for (let j = 0; j < n-i-1; j ) {
if (arr[j] > arr[j 1]) {
// 交換arr[j 1]與arr[j]
let temp = arr[j];
arr[j] = arr[j 1];
arr[j 1] = temp;
}
