The Exercises
1. The first one I found hard was the Logic-2 exercise called make_bricks. In some cases, it needs to use lots of little bricks instead of a big brick. Finally, I found it can be simply coded as following.
def make_bricks(small, big, goal):
goal = goal - 5*min(big,goal/5)
return goal-small <= 0
2. The second one I liked is the Logic-2 exercise called lone_sum. At first, I thought I should list all situation it might happen as following.
def lone_sum(a, b, c):
if a == b == c:
return 0
elif a == b:
return c
elif a == c:
return b
elif b == c:
return a
else:
return a + b + c
However, we can use 'not in' which make the script much more brief and neat.
def lone_sum(a, b, c):
sum = 0
if a not in [b,c]:
sum += a
if b not in [a,c]:
sum += b
if c not in [a,b]:
sum += c
return sum
3. I found the most hardest is list-2 exercise called sum67. A lot of cases should be taken into consideration. At first, I came up with a script as following.
def sum67(nums):
for i in nums:
if 6 in nums:
six = nums.index(6)
seven = nums.index(7)
for i in range(six,seven+1):
nums.pop(six)
return sum(nums)
However, it cannot pass if the first 7 comes before the first 6. Then, after several tries, I got the following solution which works fine!!
def sum67(nums):
sum = 0
flag = True
for i in nums:
if i == 6:
flag = False
continue
if i == 7 and not flag:
flag = True
continue
if flag:
sum += i
return sum
The Screenshots
Here are my screenshots:
