概述
1 for (int i = 0; i < arr.length - 1; i++) {
2 int index = i;
3 for (int j = i + 1; j < arr.length; j++) {
4 index = arr[index] > arr[j] ? j : index;
5 }
6 if (index != i) {
7 swap(arr,i , index);
8 }
9 }