Java版选择排序[不稳定]

原理：每次从无序序列选取最小的

复杂度：O(n^2) - O(n^2) - O(n^2) - O(1)[平均 - 最好 - 最坏 - 空间复杂度]

public void selectSort(int[] a) {if (null == a || a.length < 2) {return;}for (int i = 0; i < a.length; i++) {int k = i;for (int j = i + 1; j < a.length; j++) {if (a[j] < a[k]) {k = j;}}if (k!=i) {int temp = a[k];a[k] = a[i];a[i] = temp;}}}