Add 2017

Author: nthistle

2017/day01/day01.py

@@ -0,0 +1,8 @@
+with open("input.txt") as f:
+ s = f.read().strip()
+
+print(sum(int(s[i]) for i in range(len(s)) if s[i] == s[i-1]))
+
+n = len(s)
+
+print(sum(int(s[i]) for i in range(len(s)) if s[i] == s[(i+n//2)%n]))

2017/day02/day02.py

@@ -0,0 +1,20 @@
+with open("input.txt") as f:
+ s = f.read().strip().split("\n")
+
+import re
+
+s = [re.sub("\\s+"," ",r).split(" ") for r in s]
+s = [[int(x) for x in r] for r in s]
+
+print(sum(max(r)-min(r) for r in s))
+
+ans = 0
+for r in s:
+ for i in range(len(r)):
+ for j in range(i+1,len(r)):
+ if r[i] % r[j] == 0:
+ ans += r[i] // r[j]
+ elif r[j] % r[i] == 0:
+ ans += r[j] // r[i]
+
+print(ans)

2017/day03/day03.py

@@ -0,0 +1,44 @@
+inp = 325489
+
+s = 1
+while s*s < inp:
+ s += 2
+s -= 2
+
+v = s*s + 1
+loc = [(s//2)+1, -(s//2)]
+if v < inp:
+ loc[1] += min(inp - v, s)
+ v += min(inp - v, s)
+
+if v < inp:
+ loc[0] -= min(inp - v, s+1)
+ v += min(inp - v, s+1)
+
+if v < inp:
+ loc[1] -= min(inp - v, s+1)
+ v += min(inp - v, s+1)
+
+if v < inp:
+ loc[0] += min(inp - v, s+1)
+ v += min(inp - v, s+1)
+
+print(abs(loc[0])+abs(loc[1]))
+
+from collections import defaultdict
+
+grid = defaultdict(lambda : 0)
+grid[0,0] = 1
+loc = [0,0]
+
+dirs = [(1,0),(0,1),(-1,0),(0,-1)]
+v = 0
+while v < inp:
+ loc[0] += dirs[0][0]
+ loc[1] += dirs[0][1]
+ grid[tuple(loc)] = v = sum(grid[loc[0]+i,loc[1]+j] for i in range(-1,2) \
+ for j in range(-1,2) if (i,j) != (0,0))
+ if grid[loc[0]+dirs[1][0],loc[1]+dirs[1][1]] == 0:
+ dirs.append(dirs.pop(0))
+
+print(v)

2017/day04/day04.py

@@ -0,0 +1,7 @@
+with open("input.txt") as f:
+ s = f.read().strip().split("\n")
+
+print(sum(1 for p in s if p.count(" ")+1 == len(set(p.split(" ")))))
+
+print(sum(1 for p in s if p.count(" ")+1 == \
+ len(set("".join(sorted(pp)) for pp in p.split(" ")))))

2017/day05/day05.py

@@ -0,0 +1,29 @@
+with open("input.txt") as f:
+ s = f.read().strip().split("\n")
+
+v = [int(x) for x in s]
+idx = 0
+
+steps = 0
+while idx in range(len(v)):
+ v[idx] += 1
+ idx += v[idx] - 1
+ steps += 1
+
+print(steps)
+
+
+v = [int(x) for x in s]
+idx = 0
+
+steps = 0
+while idx in range(len(v)):
+ j = v[idx]
+ if j >= 3:
+ v[idx] -= 1
+ else:
+ v[idx] += 1
+ idx += j
+ steps += 1
+
+print(steps)

2017/day06/day06.py

@@ -0,0 +1,24 @@
+import re
+
+with open("input.txt") as f:
+ s = re.sub("\\s+"," ",f.read().strip()).split(" ")
+
+s = [int(x) for x in s]
+
+seen = {}
+
+count = 0
+while tuple(s) not in seen:
+ seen[tuple(s)] = count
+ idx = max(range(len(s)), key = lambda i : (s[i], -i))
+ value = s[idx]
+ s[idx] = 0
+ per, rem = value // len(s), value % len(s)
+ for i in range(len(s)):
+ s[i] += per
+ if (i - idx - 1) % len(s) < rem:
+ s[i] += 1
+ count += 1
+
+print(count)
+print(count - seen[tuple(s)])

2017/day07/day07.py

@@ -0,0 +1,37 @@
+with open("input.txt") as f:
+ s = f.read().strip().split("\n")
+
+weights = {}
+children = {}
+
+seen = set()
+
+for p in s:
+ pn = p[:p.find(" ")]
+ pw = int(p[p.find("(")+1:p.find(")")])
+ weights[pn] = pw
+ if "->" in p:
+ children[pn] = p[p.find("->")+3:].split(", ")
+ seen.update(children[pn])
+
+root = None
+for p in weights:
+ if p not in seen:
+ root = p
+print(root)
+
+def find(c):
+ w = weights[c]
+ if c in children:
+ cw = [find(n) for n in children[c]]
+ if -1 in cw:
+ return -1
+ w += sum(cw)
+ if len(set(cw)) != 1:
+ for i in range(len(cw)):
+ if cw[i] != cw[i-1] and cw[i] != cw[i-2]:
+ print(weights[children[c][i]] - cw[i] + cw[i-1])
+ return -1
+ return w
+
+find(root)

2017/day08/day08.py

@@ -0,0 +1,21 @@
+with open("input.txt") as f:
+ s = f.read().strip().split("\n")
+
+from collections import defaultdict
+
+reg = defaultdict(lambda : 0)
+
+m = 0
+for ins in s:
+ cmd, cnd = ins.split(" if ")
+ cnd_r, cnd_op, cnd_cmp = cnd.split(" ")
+ if eval(str(reg[cnd_r]) + cnd_op + cnd_cmp):
+ cmd_r, cmd_op, cmd_arg = cmd.split(" ")
+ if cmd_op == "inc":
+ reg[cmd_r] += int(cmd_arg)
+ elif cmd_op == "dec":
+ reg[cmd_r] -= int(cmd_arg)
+ m = max(m, reg[cmd_r])
+
+print(max(reg.values()))
+print(m)

2017/day09/day09.py

@@ -0,0 +1,34 @@
+with open("input.txt") as f:
+ s = f.read().strip()
+
+import re
+
+s = re.sub("!.","",s)
+
+in_g = False
+g_count = 0
+idx = 0
+while idx < len(s):
+ if in_g:
+ if s[idx] == ">":
+ in_g = False
+ else:
+ g_count += 1
+ else:
+ if s[idx] == "<":
+ in_g = True
+ idx += 1
+
+s = re.sub("\\<.*?\\>","",s)
+
+scores = 0
+stack = []
+for c in s:
+ if c == "{":
+ stack.append(0)
+ elif c == "}":
+ stack.pop(-1)
+ scores += len(stack) + 1
+
+print(scores)
+print(g_count)

2017/day10/day10.py

@@ -0,0 +1,42 @@
+with open("input.txt") as f:
+ s = f.read().strip()
+
+v = [int(x) for x in s.split(",")]
+
+cur = list(range(256))
+
+offset = 0
+skip = 0
+for length in v:
+ cur = cur[length:] + cur[:length][::-1]
+ cur = cur[skip:] + cur[:skip]
+ offset += length + skip
+ skip += 1
+
+offset = (-offset) % len(cur)
+cur = cur[offset:] + cur[:offset]
+
+print(cur[0]*cur[1])
+
+lengths = [ord(c) for c in s] + [17,31,73,47,23]
+
+cur = list(range(256))
+
+offset = 0
+skip = 0
+for _ in range(64):
+ for length in lengths:
+ cur = cur[length:] + cur[:length][::-1]
+ cur = cur[skip:] + cur[:skip]
+ offset = (offset + length + skip) % len(cur)
+ skip = (skip + 1) % len(cur)
+offset = (-offset) % len(cur)
+cur = cur[offset:] + cur[:offset]
+
+def xor(vals):
+ out = 0
+ for val in vals:
+ out ^= val
+ return out
+
+print("".join(hex(xor(cur[i:i+16])+256)[3:] for i in range(0,256,16)))