补充下面的程序:(查找给定的元素出现的第一个位置)arr = [1,3,5,4,2,4,6,5,1]key = 7for i in range(len(arr)):if arr[i] == key:print(i)if i == :print(-1)
补充下面的程序:(二分查找)arr= [2,5,6,8,12,15,17,23,27,31,39,40,45,56,79,90]l,r = 0,len(arr) -1n = 20while :mid =if arr[mid]n:r = mid -1else:print(mid)else:print(-1)