static void selection_sort(int[] unsorted) {
for (int i = 0; i < unsorted.Length; i++) {
int min = unsorted[i], min_index = i;
for (int j = i; j < unsorted.Length; j++) {
if (unsorted[j] < min) {
min = unsorted[j];
min_index = j;
}
}
if (min_index != i) {
int temp = unsorted[i];
unsorted[i] = unsorted[min_index];
unsorted[min_index] = temp;
}
}
}
有改进的方法，二路选择排序，一次循环中找出最大值和最小值
