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day 2 part 2

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magical 2025-12-02 07:50:21 +00:00
parent 80b0dea13b
commit a0ff488cf1
1 changed files with 33 additions and 2 deletions
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35
day02/sol.py
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@ -12,11 +12,17 @@ def solve(input):
t = 0
for lo,hi in ranges:
invalid = list(findinvalid(lo,hi))
if len(invalid) == 0:
print(lo,hi,invalid)
#if len(invalid) == 0:
# print(lo,hi,invalid)
t += sum(invalid)
print(t)
t2 = 0
for lo,hi in ranges:
invalid2 = set(findinvalid2(lo,hi))
t2 += sum(invalid2)
print(t2)
def findinvalid(lo, hi):
assert len(str(hi)) - len(str(lo)) <= 1
assert lo <= hi
@ -36,5 +42,30 @@ def findinvalid(lo, hi):
#print(lo, hi, i,B,id)
yield id
def findinvalid2(lo, hi):
assert lo <= hi,(lo,hi)
if len(str(hi)) != len(str(lo)):
assert len(str(hi)) - len(str(lo)) == 1
yield from findinvalid2(lo,10**len(str(lo))-1)
yield from findinvalid2(10**(len(str(hi))-1),hi)
return
N = len(str(hi))
for d in range(1,N):
if N%d == 0:
B = 10**d
BB = 10**(N-d)
factor = sum(10**k for k in range(0,N,d))
for i in range(lo//BB, hi//BB+1):
if i < B//10:
continue
if i >= B:
break
id = i*factor
#print(lo,hi,factor,i,id)
if lo <= id <= hi:
#assert(str(i)*(N//d) == str(id)), (i,id)
#print(lo, hi, i,B,id)
yield id
#solve("sample")
solve("input")