Day 5 of 2020 done in Python

2020/Day 5/Solution.py

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+from math import floor,ceil
+
+input_file = "input.txt"
+
+seats = []
+
+with open(input_file) as boardings:
+    line = boardings.readline()
+    while line and line != "\n":
+        row_start = 0
+        row_end = 127
+        column_start = 0
+        column_end = 7
+
+        for character in line:
+            if character == "F":
+                row_end = floor((row_start+row_end)/2)
+            elif character == "B":
+                row_start = ceil((row_start+row_end)/2)
+            elif character == "L":
+                column_end = floor((column_start+column_end)/2)
+            elif character == "R":
+                column_start = ceil((column_start+column_end)/2)
+            else: # End of line
+                seats.append(row_end*8+column_end)
+
+        line = boardings.readline()
+
+print(f"Highest seat ID : {max(seats)}")
+
+
+seats.sort()
+possible_seats = list(range(seats[0], seats[-1]+1))
+
+# There might be missing seats at the front or the back of the plane
+# thus, if we sort and create a range between the smallest and largest ID
+# and iterate over both, the number missing in the full range would be our seat.
+
+for i in range(len(seats)):
+    if seats[i] != possible_seats[i]:
+        print(f"Your seat is {possible_seats[i]}")
+        break