day 3 solutions

day03/sol.py

@@ -0,0 +1,68 @@
+import sys
+
+input = sys.stdin
+data = [line.strip() for line in input]
+
+def issymbol(c):
+    return c != '.' and not c.isalnum()
+
+def nexttosymbol(row, col):
+    for x in [col-1, col, col+1]:
+        for y in [row-1, row, row+1]:
+            if 0 <= y < len(data) and 0 <= x < len(data[y]):
+                if issymbol(data[y][x]):
+                    return True
+    return False
+
+def findgears(row, col):
+    for x in [col-1, col, col+1]:
+        for y in [row-1, row, row+1]:
+            if 0 <= y < len(data) and 0 <= x < len(data[y]):
+                if data[y][x] == '*':
+                    yield y,x
+
+
+part1 = 0
+gears = {}
+for no, line in enumerate(data):
+    places = []
+    digits = []
+    i = 0
+    while i < len(line):
+        if line[i].isdigit() and (i == 0 or not line[i-1].isdigit()):
+            j = i+1
+            while j < len(line) and line[j].isdigit():
+                j += 1
+            digits.append(int(line[i:j]))
+            places.append(list(range(i,j)))
+            i = j
+        else:
+            i += 1
+        
+    for n, pos in zip(digits, places):
+        if any(nexttosymbol(no, i) for i in pos):
+            print(n)
+            part1 += n
+
+        seen = set()
+        for i in pos:
+            for g in findgears(no,i):
+                if g not in seen:
+                    gears.setdefault(g, []).append(n)
+                    seen.add(g)
+            
+print(part1)
+
+part2 = 0
+for g, nums in gears.items():
+    if len(nums) == 2:
+        part2 += nums[0] * nums[1]
+print(part2)
+
+
+
+            
+
+    
+
+