day 20 python solution

day20/sol.py

@@ -0,0 +1,46 @@
+data = []
+for line in open("input"):
+    data.append(int(line.strip()))
+
+#data = [1, 2, -3, 3, -2, 0, 4, ]
+
+
+def mix(data, rounds=1):
+    #assert len(set(data)) == len(data)
+    copy = list(data)
+    idx = list(range(len(data)))
+
+    for _ in range(rounds):
+
+        for k in range(len(data)):
+            i = idx.index(k)
+            x = copy[i]
+            if x != 0:
+                j = (i+x) % (len(copy)-1)
+                if x < 0 and j == 0:
+                    j = len(copy)-1
+                copy.insert(j, copy.pop(i))
+                idx.insert(j, idx.pop(i))
+            else:
+                j = i
+            #print(x, i, j, copy)
+
+    return copy
+
+def answer(data):
+    i = data.index(0)
+    n = 0
+    for j in 1000, 2000, 3000:
+        x = data[(i+j)%len(copy)]
+        #print(x)
+        n += x
+    return n
+
+#print(copy)
+
+copy = mix(data)
+print(answer(copy))
+
+
+p2 = [x*811589153 for x in data]
+print(answer(mix(p2, 10)))