# C語言題庫-064 寫出二分查找的代碼。 【參考答案】 ``` int b inary_search(int* arr, int k ey, int n) { int low = 0; int h igh = n - 1 ; int m id; while (low <= high) { mid = (high + low) / 2; if (arr[mid] > k) high = mid -1 ; else if (arr[mid] < k) low = mid + 1; else return mid; } return -1; } ```