c++ 选择排序

int length = 6;
	int tmp;
	int minindex;
	int min;
	for (int i = 0; i < length; i++) {
		min = arr[i];
		minindex = i;
		for (int j = i; j < length; j++) {
			if (arr[j] < min) {
				min = arr[j];
				minindex = j;
			}
		}
		tmp = arr[i];
		arr[i] = min;
		arr[minindex] = tmp;
	}
	for (int i = 0; i < length; i++) {
	cout << arr[i] <<" ";
    }

还是使用随机数组，然后排序输出。