Add kattis prob pizzahawaii in python3 + notes

kattis/pizzahawaii/notes.md

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+A sets/dictionaries problem.
+
+Build up a dictionary `d` of possible translations for each foreign word.
+
+Whenever a new pizza is read in, the possible translations for each `w` in the foreign language should be the set intersection of the previous translations (`d[w]`) and the english ingredients in this pizza.
+
+After this is done for all pizzas, you need to run through each `w` in `d` and remove all possible candidate translations that appear in other pizzas without `w`. ie. For every input pizza, if `w` is not in the foreign ingredients, then you should remove all the english ingredients for that pizza from `d[w]`. 
+
+This runs in 0.02s in python3 (the fastest python3 submission on kattis!).

kattis/pizzahawaii/solution.py

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+def main():
+    t = int(input())
+    for _ in range(t):
+        n = int(input())
+        d = {}
+        p = []
+        for _ in range(n):
+            input() # pizza name
+            _, *u = input().split()
+            _, *v = input().split()
+            u = set(u)
+            v = set(v)
+            for w in u:
+                if w in d:
+                    d[w] &= v
+                else:
+                    d[w] = set(v)
+            p.append((u, v))
+        for u, v in p:
+            for w in d:
+                if w not in u:
+                    d[w] -= v
+        ans = []
+        for k in d:
+            for o in d[k]:
+                ans.append((k, o))
+        ans.sort()
+        for a in ans:
+            print('({}, {})'.format(*a))
+        print()
+
+if __name__ == '__main__':
+    main()