c语言折半查找法代码怎么写

#include <stdio.h>

int binarySearch(int arr[], int n, int key) {
int low = 0, high = n - 1;
while (low <= high) {
int mid = (low + high) / 2;
if (arr[mid] == key) {
return mid;
}
else if (arr[mid] < key) {
low = mid + 1;
}
else {
high = mid - 1;
}
}
return -1; // key not found
}

int main() {
int arr[] = {2, 4, 6, 8, 10, 12, 14, 16, 18, 20};
int n = sizeof(arr) / sizeof(arr[0]);
int key = 12;
int index = binarySearch(arr, n, key);
if (index != -1) {
printf(“Element %d found at index %d”, key, index);
}
else {
printf(“Element not found”);
}
return 0;
}