每周算法编程联系1

Posted 2020-11-21 linlianhuan

在一个有序的列表中，查找指定数字的索引位置：

mylist = [1,2,3,4,5,6,7,8,9,10,11]

# list_len = mylist.__len__()
# print list_len


def find_number_index(list,target,start):
    length = list.__len__()
    print "--- "+str(length)
    mid = int(length/2)

    if mid <=1 :
        if list[mid] == target:
            return "find index: " + str(mid+ start)
        elif list[mid-1] == target:
            return "find index: " + str(mid -1+ start)
        elif length == 3  and list[mid+1] == target  :
            return "find index: " + str(mid + 1 + start)
        else:
            return "could not mad a number"
    elif list[mid] == target:
            print " mylist[mid] == target "
            return  "find index: " + str(mid + start)
    elif list[mid] > target:
        print str(list[mid]) + " mylist[mid] > target "
        list_min = list[:mid]
        print list_min
        return find_number_index(list_min,target,start)
    else :
        print " mylist[mid] < target "
        list_max = list[mid:]
        print list_max
        return find_number_index(list_max,target, start+mid)


if __name__=="__main__":
    print find_number_index(mylist,3, 0)