int fun(int a[], int low, int high,int k) // k需要找的数{ int mid = low + (high - low) / 2; if (a[mid] == k) { return mid; } else if(a[mid]<k&&mid<high) { return fun(a, mid + 1, high, k); } else if(a[mid]>k&&mid>low) { return fun(a, low, mid - 1, k); } else { return -1; }}int ...