2017 day 3

Author: vmaffet

2017/3/sol.py

@@ -0,0 +1,71 @@
+#!/usr/bin/python3
+import argparse
+from collections import defaultdict
+
+parser = argparse.ArgumentParser()
+parser.add_argument("n", help="your number", type=int)
+parser.add_argument("-p", "--part", help="part number", type=int, default=1)
+args = parser.parse_args()
+
+if args.part == 1:
+    
+    n = args.n
+    m = 1
+    r = 0
+
+    while m < n:
+       r += 1
+       m += 8*r
+
+    x, y = r, -r
+
+    if n <= m - 2*r:
+        m -= 2*r
+        x -= 2*r
+        if n <= m - 2*r:
+            m -= 2*r
+            y += 2*r
+            if n <= m - 2*r:
+                m -= 2*r
+                x += 2*r
+                y -= m - n
+            else:
+                x += m - n
+        else:
+            y += m - n 
+    else:
+        x -= m - n
+
+    print(abs(x) + abs(y))
+    
+elif args.part == 2:
+    
+    n = args.n
+    x, y = 1, 0
+    res = 1
+    val = {(0,0):1, (1,0):1}
+    val = defaultdict(lambda:0, val)
+    while res < n:
+        if y < 0 and x >= y  and x <= -y:
+            x += 1
+        elif x > 0 and y < x:
+            y += 1
+        elif y > 0 and x > -y:
+            x -= 1
+        elif x < 0 and y > x:
+            y -= 1
+
+        res = val[(x-1, y+1)] \
+             + val[(x  , y+1)] \
+             + val[(x+1, y+1)] \
+             + val[(x-1, y  )] \
+             + val[(x+1, y  )] \
+             + val[(x-1, y-1)] \
+             + val[(x  , y-1)] \
+             + val[(x+1, y-1)]
+
+        val[(x,y)] = res
+        #print(res)
+        
+    print(res)
+