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def do(input, phases=100, repeats=1):
nums = []
for i in range(repeats):
nums += [int(x) for x in input[0].strip()]
for phase in range(phases):
#print(phase)
new_list = []
for i in range(len(nums)): # position of number to calculate
new_num = 0
for k in range(len(nums)):
mod = (k+1) % (4*(i+1))
if mod >= i + 1 and mod < 2*i + 2:
new_num += nums[k]
elif mod >= 3*i + 3:
new_num -= nums[k]
new_list.append(abs(new_num) % 10)
nums = new_list
return "".join([str(n) for n in nums[:8]])
def pt1(input):
return do(input, phases=100, repeats=1)
def pt2(input, phases=100, repeats=10000):
offset = int(input[0][:7])
nums = []
for i in range(repeats):
nums += [int(x) for x in input[0].strip()]
nums = nums[offset:]
for phase in range(phases):
#print(phase)
nums = nums[::-1]
new_nums = []
n = sum(nums)
while len(nums) != 0:
new_nums.append(abs(n) % 10)
n -= nums.pop()
nums = new_nums
return "".join([str(n) for n in nums[:8]])
if __name__ == "__main__":
input = open("../input/16", "r").readlines()
ans1 = pt1(input)
ans2 = pt2(input)
print(ans1)
print(ans2)
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