Google python list2.py (python 2.7)
#!/usr/bin/python -tt# D. Given a list of numbers, return a list where
# all adjacent == elements have been reduced to a single element,
# so returns . You may create a new list or
# modify the passed in list.
def remove_adjacent(nums):
for num in nums:
if nums.index(num)<=len(nums)-2 and num ==nums:
nums.remove(num)
return nums
# E. Given two lists sorted in increasing order, create and return a merged
# list of all the elements in sorted order. You may modify the passed in lists.
# Ideally, the solution should work in "linear" time, making a single
# pass of both lists.
# solution 1:
def linear_merge(list1, list2):
return sorted(list1+list2)
# solution 2:
def linear_merge(list1, list2):
temp=[]
while len(list1)>0 and len(list2)>0:
if list1[-1] > list2[-1]:
temp.append(list1.pop(-1))
else:
temp.append(list2.pop(-1))
temp.extend(sorted(list1,reverse=True))
temp.extend(sorted(list2,reverse=True))
temp.reverse()
return temp
# Note: the solution above is kind of cute, but unforunately list.pop(0)
# is not constant time with the standard python list implementation, so
# the above is not strictly linear time.
# An alternate approach uses pop(-1) to remove the endmost elements
# from each list, building a solution list which is backwards.
# Then use reversed() to put the result back in the correct order. That
# solution works in linear time, but is more ugly.
# Simple provided test() function used in main() to print
# what each function returns vs. what it's supposed to return.
def test(got, expected):
if got == expected:
prefix = ' OK '
else:
prefix = 'X '
print '%s got: %s expected: %s' % (prefix, repr(got), repr(expected))
# Calls the above functions with interesting inputs.
def main():
print 'remove_adjacent'
test(remove_adjacent(), )
test(remove_adjacent(), )
test(remove_adjacent([]), [])
print 'linear_merge'
test(linear_merge(['aa', 'xx', 'zz'], ['bb', 'cc']),
['aa', 'bb', 'cc', 'xx', 'zz'])
test(linear_merge(['aa', 'xx'], ['bb', 'cc', 'zz']),
['aa', 'bb', 'cc', 'xx', 'zz'])
test(linear_merge(['aa', 'aa'], ['aa', 'bb', 'bb']),
['aa', 'aa', 'aa', 'bb', 'bb'])
if __name__ == '__main__':
main()
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