public class SelectionSort {
    public static void sort(Comparable[] a){
        for(int i = 0; i < a.length-1; i++){
            int minIndex = i;//设最小值所对应位置
            for(int j = i + 1; j < a.length; j++){
                //如果该元素后的值更大，则改变此时最小值对应位置
                if(greater(a[minIndex],a[j])){
                    minIndex = j;
                }
            }
            exch(a,i,minIndex);//交换首位元素和最小值
        }
    }
    private static boolean greater(Comparable x, Comparable y){
        return x.compareTo(y) > 0;
    }
    private static void exch(Comparable[] a, int i, int j){
        Comparable temp;
        temp = a[i];
        a[i] = a[j];
        a[j] = temp;
    }
}

public class SelectionSortTest {
    public static void main(String[] args) {
        Integer[] arr = {4,6,8,7,9,2,10,1};
        BubbleSort.sort(arr);
        System.out.println(Arrays.toString(arr));
    }
}

public class test {
    public static void main(String[] args) {
        int arr[] = {4,5,6,3,2,1};
        int temp = 0;
        System.out.println("原数组是");
        for (int i = 0; i < arr.length; i++) {
            System.out.print(arr[i] + " ");
        }
        for(int i = 0; i <arr.length; i++){
          int index = i;
            for(int j = i+1; j < arr.length; j++){
              if(arr[index] > arr[j]) {
                index = j;
              }
            }
           if(index != i){
                    temp = arr[i];
                    arr[i] = arr[index];
                    arr[index] = temp;
                } 
        }
        System.out.println("\n排序后数组是");
        for (int i = 0; i < arr.length; i++) {
            System.out.print(arr[i] + " ");
        }
    }
}