31 lines
422 B
Python
31 lines
422 B
Python
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import time
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# T[i] += value
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def add(t, i, value):
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while i < len(t):
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t[i] += value
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i |= i + 1
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# sum[0..i]
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def sum(t, i):
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res = 0
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while i >= 0:
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res += t[i]
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i = (i & (i + 1)) - 1
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return res
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def test():
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start = time.time()
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n = 100000
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t = [0] * n
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for i in range(n):
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add(t, i, 1)
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assert n == sum(t, n - 1)
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print(time.time() - start)
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test()
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