1 files changed, 51 insertions, 0 deletions
diff --git a/20/py/d05.py b/20/py/d05.py
new file mode 100644
index 0000000..d72d3ee
--- /dev/null
+++ b/20/py/d05.py
@@ -0,0 +1,51 @@
+#!/usr/bin/env python3
+import sys
+
+
+def bin(lo, hi, x):
+    mid = (hi+lo)//2
+    if x in "BR":
+        # upper
+        return (mid + 1, hi)
+    else:
+        return (lo, mid)
+
+
+def pt1(_in):
+    highest = 0
+    for board in _in:
+        r_lo, r_hi = 0, 127
+        for r in board[:7]:
+            r_lo, r_hi = bin(r_lo, r_hi, r)
+        c_lo, c_hi = 0, 7
+        for c in board[7:]:
+            c_lo, c_hi = bin(c_lo, c_hi, c)
+        i = r_lo*8+c_lo
+        if i > highest:
+            highest = i
+    return highest
+
+
+def pt2(_in):
+    seats = []
+    for board in _in:
+        r_lo, r_hi = 0, 127
+        for r in board[:7]:
+            r_lo, r_hi = bin(r_lo, r_hi, r)
+        c_lo, c_hi = 0, 7
+        for c in board[7:]:
+            c_lo, c_hi = bin(c_lo, c_hi, c)
+        seats.append(r_lo*8+c_lo)
+    seats = sorted(seats)
+    for i in range(len(seats) - 1):
+        if seats[i+1] == seats[i] + 2:
+            return seats[i] + 1
+
+
+if __name__ == "__main__":
+    if len(sys.argv) > 1:
+        input = open(sys.argv[1], "r").readlines()
+    else:
+        input = open("../input/05", "r").readlines()
+    print(pt1(input))
+    print(pt2(input))