Add solution for day 14

AoC2021/code/AoC14.py

@@ -0,0 +1,49 @@
+#!/usr/bin/env python3
+
+import sys
+from collections import Counter
+from copy import deepcopy
+
+def step(cons,s):
+    for _ in range(s):
+        ncons = {}
+        for (a,b),v in cons.items():
+            if (a, rules[a+b]) not in ncons: ncons[(a, rules[a+b])] = 0
+            if (rules[a+b], b) not in ncons: ncons[(rules[a+b], b)] = 0
+            ncons[(a, rules[a+b])] += v
+            ncons[(rules[a+b],b)] += v
+        cons = deepcopy(ncons)
+    return cons
+
+def countp(cons):
+    ex = {}
+    for k in nex.keys():
+        ex[k[0]] = 0
+        ex[k[1]] = 0
+    ex[start[0]] += 1
+    ex[start[-1]] += 1
+    for k,v in nex.items():
+        ex[k[0]] += v
+        ex[k[1]] += v
+    return ex
+
+if __name__ == '__main__':
+    start, rules = open(sys.argv[1]).read().split('\n\n')
+    rules = [r.split(' -> ') for r in rules.split('\n')]
+    rules = {a[0]:a[1] for a in rules[:-1]}
+    nex = {}
+    for a,b in zip(start[:-1],start[1:]):
+        if (a,b) not in nex: nex[(a,b)] = 0
+        nex[(a,b)] +=1
+    # challenge 1
+    nex = step(nex,10)
+    res = countp(nex)
+    res1 = str(max(res.values())//2-min(res.values())//2)
+    print("challenge 1:" +"\n" +  res1 + "\n")
+
+    # challenge 2
+    nex = step(nex,30)
+    res = countp(nex)
+    res2 = str(max(res.values())//2-min(res.values())//2)
+    print("challenge 2:" +"\n" +  res2 + "\n")
+