c++二分查找猜数字

以下是两种C++二分查找猜数字的例子：
1. 递归实现二分查找

#include <iostream>
using namespace std;

int bs(int left, int right, int x, int a[]) {
    int mid = (left + right) / 2;
    if (x < a[mid]) {
        return bs(left, mid - 1, x, a);
    } else if (x > a[mid]) {
        return bs(mid + 1, right, x, a);
    } else {
        return mid;
    }
}

int main() {
    int n, x;
    cin >> n >> x;
    int a[105];
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }
    cout << bs(0, n, x, a);
    return 0;
}

2. 非递归实现二分查找

#include <iostream>
using namespace std;

int main() {
    int n, x;
    cin >> n >> x;
    int a[105];
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }
    int head = 0, tail = n;
    while (head != tail) {
        int mid = (head + tail) / 2;
        if (a[mid] > x) {
            tail = mid;
            continue;
        }
        if (a[mid] <= x) {
            head = mid + 1;
            continue;
        }
    }
    cout << head - 1;
    return 0;
}