C++二分查找+输入数组+冒泡排序

代码自取：
运用了很基础的手法写，运行没错误

#include 
using namespace std;
int main() {
	int arr[10]; int i = 0;
	int length = sizeof(arr) / sizeof(arr[0]);
	for( i=0;i> arr[i];
	cout << "原数组等于：" << endl;
	for (i = 0; i < length; i++)
		cout << arr[i] << " ";
	    cout << endl;
		for (int i = 0; i < length - 1; i++) {
			for (int j = 0; j < length - 1 - i; j++) {
				if (arr[j] > arr[j + 1])
				{
					int t = arr[j];
					arr[j] = arr[j + 1];
					arr[j + 1] = t;
				}
			}
		}
	cout << "从小排列到大的数组等于：" << endl;
	for (i = 0; i < length; i++)
		cout << arr[i] << " ";
	cout << endl;
	int k; cin >> k;
	int left=0; int right=length-1;
	
	while (left <= right) {
		int mid = (left + right) / 2;
		if (arr[mid] < k) {
			left = mid + 1;//要后半部分
		}
		else if (arr[mid] > k) {
			right = mid - 1;//要前半部分
		}
		else {
			cout << "数组找到这个数了，下标是： " << mid;
			break;
		}
	}
	if (left > right) {
		cout << "数组中找不到这个数";
	}
	return 0;
}