initial commit

2021/Day8/Day8_2_Reddit.py

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+def AOC_8_a():
+    with open("src/input8.txt") as file:
+        lines = file.read().splitlines()
+        lines = [x.split(" | ")[1].split(' ') for x in lines]
+        total = 0
+        for line in lines:
+            for item in line:
+                if len(item) == 2 or len(item) == 3 or len(item) == 4 or len(item) == 7:
+                    total += 1
+        print(total)
+
+
+def AOC_8_b():
+    with open("input.txt") as file:
+        lines = file.read().splitlines()
+        lines = [x.split(" | ") for x in lines]
+        total = 0
+        for (lefthand, righthand) in lines:
+            lefts = lefthand.split(' ')
+            digits = fill_dict(lefts)
+            digits["2"] = find_two(digits["1"], digits["len5"] + digits["len6"])
+            digits["9"] = find_nine(digits["4"], digits["len6"])
+
+            digits["len6"].remove(digits["9"])
+
+            digits["5"] = find_five(digits["2"], digits["len5"])
+
+            digits["len5"].remove(digits["2"])
+            digits["len5"].remove(digits["5"])
+
+            digits["3"] = find_three(digits["len5"])
+            digits["6"] = find_six(digits["5"], digits["len6"])
+
+            digits["len6"].remove(digits["6"])
+
+            digits["0"] = find_zero(digits["len6"])
+
+            del digits["len5"]
+            del digits["len6"]
+
+            number = ""
+            for item in righthand.split(' '):
+                item = "".join(sorted(item))
+                for key, value in digits.items():
+                    if (value == item):
+                        number += key
+            print(number)
+            total += int(number)
+        print(total)
+
+
+def pd(dict):
+    for (key, value) in dict.items():
+        print(key, ": ", value)
+
+
+# 0 is the last number to find, and is just the last remaining not used string
+def find_zero(candidates):
+    return candidates[0]
+
+
+# 2 is the only digit that shares a unique single segment with 1 (5 and 6 also share
+# a single segment with 1, but they're thus not unique) among unknown digits. We need both len5 and len6
+# to check for this uniqueness.
+def find_two(segment, candidates):
+    az = {x: shares_only_one_segment(x, segment) for x in candidates if shares_only_one_segment(x, segment) is not None}
+    return least_frequent(az)
+
+
+# 3 will be the only len5 segment not assigned at this point
+def find_three(candidates):
+    return candidates[0]
+
+
+# 5 is the only digit that shares three segments with 2
+def find_five(segment, candidates):
+    for can in candidates:
+        if (shares_x_segments(segment, can, 3)):
+            return can
+
+
+# 6 is the only digit that shares five segments with 5
+def find_six(segment, candidates):
+    for can in candidates:
+        if (shares_x_segments(segment, can, 5)):
+            return can
+
+
+# 9 is the only digit that shares four segments with 4
+def find_nine(segment, candidates):
+    for can in candidates:
+        if (shares_x_segments(segment, can, 4)):
+            return can
+
+
+def least_frequent(dict):
+    list = [value for (key, value) in dict.items()]
+    lowest_value = min(set(list), key=list.count)
+
+    for key, value in dict.items():
+        if (lowest_value == value):
+            return key
+
+
+def shares_only_one_segment(segment, candidate):
+    total = 0
+    for a in segment:
+        for b in candidate:
+            if (a == b):
+                total += 1
+                shared = a
+    return shared if total == 1 else None
+
+
+def shares_x_segments(segment, candidate, x):
+    total = 0
+    for seg in segment:
+        for can in candidate:
+            if (seg == can):
+                total += 1
+    return total == x
+
+
+def fill_dict(lefts):
+    digits = {"len5": [], "len6": []}
+    for num in lefts:
+        num = "".join(sorted(num))
+        if (len(num) == 2):
+            digits["1"] = num
+        if (len(num) == 4):
+            digits["4"] = num
+        if (len(num) == 3):
+            digits["7"] = num
+        if (len(num) == 7):
+            digits["8"] = num
+        if (len(num) == 5):
+            digits["len5"].append(num)
+        if (len(num) == 6):
+            digits["len6"].append(num)
+    return digits
+
+if __name__ == '__main__':
+    AOC_8_b()