Console.WriteLine() Cosole.ReadLine() int[] a = { 8, 6, 4, 3, 1 };for (int i = 0;
i < a.Length - 1; i++) {//下标的赋值
int min = i;for (int j = i; j < a.Length; j++) {//比较大小if (a [min] > a [j]) {min = j;}
}//交换位置int b = a [i];a [i] = a [min];
a [min] = b;}for (int i = 0; i < a.Length; i++) {Console.Write (a [i] + " ");}
Console.WriteLine ();int[] a ={ , 5, 6, 8, 9 };
int first = 0;int last = a.Length - 1;int mid = 0;//要查找的元素int num = 9;while (first <= last) {
mid = (first + last) / 2;if (num > a [mid]) {first = mid + 1;} else if
(num < a [mid]) {last = mid - 1;} else {
break;}if (first > last) {Console.WriteLine ("查无此数");} else {Console.WriteLine
("数组中第{0}位置是{1}", mid, a [mid]);
}