Update readme and lib and start 2015.

.gitignore

@@ -1,5 +1,6 @@
 # ---> Python
 # Byte-compiled / optimized / DLL files
+*.txt
 __pycache__/
 *.py[cod]
 *$py.class

2015/d1.py

@@ -0,0 +1,22 @@
+from lib import *
+
+data = open(0).read()
+
+part_2 = True
+
+floor = 0
+for i, c in enumerate(data):
+    if c == "(":
+        floor += 1
+    elif c == ")":
+        floor -= 1
+    else:
+        print(c)
+        assert False
+
+    if part_2 and floor == -1:
+        print(i + 1)
+        break
+
+if not part_2:
+    print(floor)

2015/d2.py

@@ -0,0 +1,19 @@
+from lib import *
+
+data = open(0).readlines()
+
+part_1 = True
+if part_1:
+    a = 0
+    for line in data:
+        l, w, h = list(map(int, line.split("x")))
+        slack = min([l * w, w * h, h * l])
+        a +=  (2*l*w + 2*w*h + 2*h*l + slack)
+else: 
+    a = 0
+    for line in data:
+        l, w, h = list(map(int, line.split("x")))
+        sd = min([2 * (l + w), 2 * (w + h), 2 * (h + l)])
+        a +=  sd + (l * w * h)
+
+print(a)

2015/d3.py

@@ -0,0 +1,41 @@
+import sys
+from lib import *
+
+data = open(0).read()
+
+part_1 = False
+
+DIRS = {
+    "^": (-1, 0),
+    ">": (0, 1),
+    "v": (1, 0),
+    "<": (0, -1),
+}
+
+if part_1:
+    pos = (0, 0)
+    poss = set([pos])
+
+    for c in data:
+        d = DIRS[c]
+        pos = pos[0] + d[0], pos[1] + d[1]
+        poss.add(pos)
+
+    print(len(poss))
+    sys.exit(0)
+
+a = (0, 0)
+b = (0, 0)
+poss = set([a, b])
+for i, c in enumerate(data):
+    if i % 2 == 0:
+        d = DIRS[c]
+        a = a[0] + d[0], a[1] + d[1]
+        poss.add(a)
+    else:
+        d = DIRS[c]
+        b = b[0] + d[0], b[1] + d[1]
+        poss.add(b)
+
+print(len(poss))
+sys.exit(0)

2015/d4.py

@@ -0,0 +1,22 @@
+from lib import *
+import hashlib
+
+part_1 = True
+
+if part_1:
+    digits = 5
+else:
+    digits = 6
+
+data = open(0).read().strip()
+
+for i in range(10**9):
+    text = data + str(i)
+    md5_hash = hashlib.md5(text.encode()).hexdigest()
+    for c in md5_hash[:digits]:
+        if c != "0":
+            break
+    else:
+        print(i)
+        break
+

2015/d5.py

@@ -0,0 +1,53 @@
+from lib import *
+
+data = open(0).read()
+
+part_1 = True
+if part_1:
+    res = 0
+    for line in data.splitlines():
+        vc = 0
+        for c in line:
+            if c in "aoeui":
+                vc += 1
+        if vc < 3:
+            continue
+
+        prev = None
+        for c in line:
+            if c == prev:
+                break
+            prev = c
+        else:
+            continue
+
+        contains = False
+        ss = ["ab", "cd", "pq", "xy"]
+        for s in ss:
+            if s in line:
+                contains = True
+
+        if contains:
+            continue
+        res += 1
+    print(res)
+else:
+    res = 0
+    for line in data.splitlines():
+        pairs = {}
+        for i in range(0, len(line) - 1):
+            p = line[i:i+2]
+            if p in pairs and i > pairs[p] + 1:
+                break
+            if not p in pairs:
+                pairs[p] = i
+        else:
+            continue
+
+        for i in range(0, len(line) - 2):
+            if line[i] == line[i + 2]:
+                break
+        else:
+            continue
+        res += 1
+    print(res)

2015/lib.py

@@ -0,0 +1 @@
+../lib.py

README.md

@@ -1,3 +1,12 @@
 # aocpy
 
-Help scripts for solving Advent of Code challenges in Python.
+Solutions and accompanying utility scripts for Advent of Code challenges
+written in Python.
+
+# 2015
+
+- Day 1: 3:10
+- Day 2: 5:24 :/ 
+- Day 3: 7:26 ... :/
+- Day 4: 5:11 ...
+- Day 5: 14:05 o.O

lib.py

@@ -11,6 +11,9 @@ INF = float("inf")
 fst = lambda l: l[0]
 snd = lambda l: l[1]
 
+def nth(n):
+    return lambda l: l[n]
+
 def maps(f, xs):
     if isinstance(xs, list):
         return [maps(f, x) for x in xs]
@@ -132,7 +135,7 @@ class Input:
     def lines(self) -> list[str]:
         return self.text.splitlines()
 
-    def paras(self) -> list[list[str]]:
+    def paras(self) -> list[str]:
         return [p for p in self.text.split("\n\n")]
 
     def grid2(self) -> Grid2D:
@@ -172,11 +175,10 @@ def lcm(numbers: list[int]) -> int:
 
 def str_to_int(line: str) -> int:
     line = line.replace(" ", "")
-    r = re.compile(r"-?\d+")
+    r = re.compile(r"(-?\d+)")
     m = r.findall(line)
-    assert len(m) == 0, "str_to_int no int"
-    assert len(m) > 1, "str_to_int multiple ints"
-    return int(m[0])
+    (x,) = m
+    return int(x)
 
 def str_to_ints(line: str) -> list[int]:
     r = re.compile(r"-?\d+")
@@ -233,3 +235,8 @@ def shoelace_area(corners):
         x2, y2 = corners[(i + 1) % n]
         area += (x1 * y2) - (x2 * y1)
     return abs(area) / 2.0
+
+def extract_year_and_date(scriptname) -> tuple[str, str]:
+    r = re.compile(r"aoc(\d\d\d\d)/d(\d+).py")
+    [(year, day)] = r.findall(scriptname)
+    return (year, day)