forked from YovM/Algorithms
36 lines
1.0 KiB
Python
36 lines
1.0 KiB
Python
def is_sum_subset(arr: list[int], required_sum: int) -> bool:
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"""
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>>> is_sum_subset([2, 4, 6, 8], 5)
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False
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>>> is_sum_subset([2, 4, 6, 8], 14)
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True
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"""
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# a subset value says 1 if that subset sum can be formed else 0
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# initially no subsets can be formed hence False/0
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arr_len = len(arr)
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subset = [[False] * (required_sum + 1) for _ in range(arr_len + 1)]
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# for each arr value, a sum of zero(0) can be formed by not taking any element
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# hence True/1
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for i in range(arr_len + 1):
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subset[i][0] = True
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# sum is not zero and set is empty then false
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for i in range(1, required_sum + 1):
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subset[0][i] = False
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for i in range(1, arr_len + 1):
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for j in range(1, required_sum + 1):
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if arr[i - 1] > j:
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subset[i][j] = subset[i - 1][j]
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if arr[i - 1] <= j:
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subset[i][j] = subset[i - 1][j] or subset[i - 1][j - arr[i - 1]]
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return subset[arr_len][required_sum]
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if __name__ == "__main__":
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import doctest
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doctest.testmod()
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