package selectionSort;

public class SelectionSortImpl {

	/*
	 * 每一趟从待排序的数据元素中选出最小（或最大）的一个元素，顺序放在已排好序的数列的最后，直到全部待排序的数据元素排完。 选择排序是不稳定的排序方法
	 */
	public static int[] selectionSort(int[] arr) {

		int len = arr.length;
		int temp = Integer.MAX_VALUE;
		int idx = -1;
		for (int j = 0; j < len; j++) {
			for (int i = j; i < len; i++) {
				if (i == j) {
					temp = arr[i];
					idx = i;
				} else if (arr[i] < temp) {
					temp = arr[i];
					idx = i;
				}
			}
			/*
			 * every time put the smallest element in the sorted order list via
			 * exchanging the the first unsorted element with the mark smallest
			 * element
			 */
			if (idx != j) {
				arr[idx] = arr[j];
				arr[j] = temp;
			}
		}
		return arr;
	}
}

package selectionSort;

import java.util.Arrays;


public class TestSelectionSort {

	public static void main(String[] args) {
		int[] arr = new int[] { 9, 8, 7, 6, 5, 4, 2, 1 };
		System.out.println("The unsorted array is                          : "
				+ Arrays.toString(arr));
		System.out.println("The sorted array with bubble sort algorithm is : "
				+ Arrays.toString(SelectionSortImpl.selectionSort(arr)));
	}

}

/*运行结果
The unsorted array is                                            : [9, 8, 7, 6, 5, 4, 2, 1]
The sorted array with selection sort algorithm is : [1, 2, 4, 5, 6, 7, 8, 9]
*/