编辑代码

#include <stdio.h>

// 二分查找函数
int binarySearch(int arr[], int left, int right, int num) {
    while (left <= right) {
        int mid = left + (right - left) / 2;

        if (arr[mid] == num)
            return mid;
        // 若查找值在左半部分，缩小右边界，否则缩小左边界
        if (arr[mid] < num)
            right = mid - 1;      
        else
             left = mid + 1; 
    }
    return -1;
}

int main() {
    int arr[] = {85, 63, 52, 34, 25, 17, 6};
    int n = sizeof(arr) / sizeof(arr[0]);
    int num = 6;

    int location = binarySearch(arr, 0, n - 1, num);
    if (location != -1)
        printf(" %d 是数组的第 %d\t 个元素", num, location + 1);
    else
        printf(" %d 不在数组中", location);

    return 0;
}