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;}