04.1, 04.2 python

04/04.py

@@ -0,0 +1,26 @@
+
+d = [(i, j) for i in range(-1, 2) for j in range(-1, 2) if not i==j==0]
+p = {"MSMS", "MSSM", "SMMS", "SMSM"}
+
+def f(i, j, w, di, dj):
+    if len(w)==0:
+        return True
+    if data[i][j]!=w[0]:
+        return False
+    return f(i+di, j+dj, w[1:], di, dj)
+
+data = open("input.txt").read().strip().split("\n")
+
+assert len(set(len(x) for x in data))==1
+
+for i in range(len(data)):
+    data[i] = '.'+data[i]+'.'
+data.append('.'*(len(data[0])+2))
+data.insert(0, '.'*len(data[0]))
+
+xs = [(i, j) for i in range(len(data[0])) for j in range(len(data)) if data[i][j]=='X']
+print(sum(1 for i, j in xs for di, dj in d if f(i, j, 'XMAS', di, dj)))
+
+As = [(i, j) for i in range(len(data)) for j in range(len(data[0])) if data[i][j]=="A"]
+cs = [(data[i-1][j-1], data[i+1][j+1], data[i-1][j+1], data[i+1][j-1]) for i, j in As]
+print(sum(1 for x in cs if ''.join(x) in p))