day 09.2024

2024/day09/day09a.py

@@ -0,0 +1,67 @@
+import sys
+from collections import deque
+
+def Checksum(arr):
+    total = 0
+    for n, num in enumerate(arr):
+        if num != None:
+            total += n * num
+    return total
+
+L = open('/home/bandeira/git.bandeira/aoc/2024/day09/input.day09').read().strip().split('\n')
+SPACES =  []
+FILES = []
+l = L[0]
+pos = 0
+line = []
+file = True
+fid = 0
+for ch in list(l):
+    if file == True:
+        line.extend([fid for _ in range(int(ch))])
+        FILES.append((fid, int(ch), pos))
+        fid += 1
+    else:
+        line.extend([None for _ in range(int(ch))])
+        SPACES.append((pos, int(ch)))
+    pos += int(ch)
+    file ^= True
+LEN = pos
+
+dq = deque(line)
+nl = []
+while dq:
+    h = dq.popleft()
+    if h == None:
+        while dq and h == None:
+            h = dq.pop()
+    if h != None:
+        nl.append(h)
+print(Checksum(nl))
+
+p2 = [None] * LEN
+
+for item in reversed(FILES):
+    num, req, atpos = item
+    moved = False
+    for s in range(len(SPACES)):
+        spos, slen = SPACES[s]
+        if spos > atpos:
+            break
+        if slen >= req:
+            pos = spos
+            SPACES[s] = (spos + req, slen - req)
+            for _ in range(req):
+                p2[pos] = num
+                pos += 1
+            moved = True
+            if SPACES[s][1] == 0:
+                del SPACES[s]
+            break
+
+    if not moved:
+        pos = item[2]
+        for _ in range(req):
+            p2[pos] = item[0]
+            pos += 1
+print(Checksum(p2))