diff --git a/README.md b/README.md index ebea961..570905f 100644 --- a/README.md +++ b/README.md @@ -2250,12 +2250,57 @@ def return_sum():
How do you swap values between two variables?
+``` x, y = y, x +``` +
-How to check if all the elements in a given lists are unique? so [1, 2, 3] is unique but [1, 1, 2, 3] is not unique but we 1 twice
-
+How to check if all the elements in a given lists are unique? so [1, 2, 3] is unique but [1, 1, 2, 3] is not unique because 1 exists twice
+ + +There are many ways of solving this problem: +# Note: :list and -> bool are just python typings, they are not needed for the correct execution of the algorithm. + +Taking advantage of sets and len: + +``` +def is_unique(l:list) -> bool: + return len(set(l)) == len(l) +``` + +This one is can be seen used in other programming languages. + +``` +def is_unique2(l:list) -> bool: + seen = [] + + for i in l: + if i in seen: + return False + seen.append(i) + return True +``` + +Here we just count and make sure every element is just repeated once. + +``` +def is_unique3(l:list) -> bool: + for i in l: + if l.count(i) > 1: + return False + return True +``` + +This one might look more convulated but hey, one liners. + +``` +def is_unique4(l:list) -> bool: + return all(map(lambda x: l.count(x) < 2, l)) +``` + +
What _ is used for in Python?
@@ -2457,7 +2502,7 @@ will always return None regardless of the operations, therefore ``` def sum(a, b): - global C + global c c = a + b >>> None