add: day4

apollod4.py

@@ -0,0 +1,48 @@
+with open("src/bin/d4p2_custom.txt", "r") as inputFile:
+    lines = inputFile.read().split("\n")
+
+# part 1
+
+horiz, verts = 0, 0
+cols = [""]*len(lines)
+for i, row in enumerate(lines):
+    horiz += row.count("XMAS") + row.count("SAMX")
+    for j, c in enumerate(row):
+        cols[j] += c
+
+for col in cols:
+    verts += col.count("XMAS") + col.count("SAMX")
+
+diags = 0
+for lineIndex, line in enumerate(lines):
+    if lineIndex > len(lines)-4:
+        break
+    for colIndex in range(len(line) - 3):
+        if lines[lineIndex][colIndex] in "SX":
+            downRight = "".join(lines[lineIndex+n][colIndex+n] for n in range(4))
+            if downRight in {"XMAS", "SAMX"}:
+                diags += 1
+    for colIndex in range(3, len(line)):
+        if lines[lineIndex][colIndex] in "SX":
+            downLeft = "".join(lines[lineIndex+n][colIndex-n] for n in range(4))
+            if downLeft in {"XMAS", "SAMX"}:
+                diags += 1
+
+print(horiz + verts + diags)
+
+# part 2
+xmases = 0
+for rowIndex, line in enumerate(lines):
+    for colIndex, c in enumerate(line):
+        if c == "A":
+            try:
+                surrounds = lines[rowIndex-1][colIndex-1] + \
+                            lines[rowIndex-1][colIndex+1] + \
+                            lines[rowIndex+1][colIndex-1] + \
+                            lines[rowIndex+1][colIndex+1]
+                if surrounds in {"SSMM", "MMSS", "MSMS", "SMSM"}:
+                    xmases += 1
+            except IndexError:
+                pass
+
+print(xmases)