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Add minmum path sum (TheAlgorithms#5882)
* commit on 'shortest_path_sum' * minimum_path_sum updated * commit to 'minimum_path_sum' * added description to minimum_path_sum * bot requirements fixed for * Update minimum_path_sum.py * Update minimum_path_sum.py Co-authored-by: John Law <[email protected]>
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def min_path_sum(grid: list) -> int: | ||
""" | ||
Find the path from top left to bottom right of array of numbers | ||
with the lowest possible sum and return the sum along this path. | ||
>>> min_path_sum([ | ||
... [1, 3, 1], | ||
... [1, 5, 1], | ||
... [4, 2, 1], | ||
... ]) | ||
7 | ||
>>> min_path_sum([ | ||
... [1, 0, 5, 6, 7], | ||
... [8, 9, 0, 4, 2], | ||
... [4, 4, 4, 5, 1], | ||
... [9, 6, 3, 1, 0], | ||
... [8, 4, 3, 2, 7], | ||
... ]) | ||
20 | ||
>>> min_path_sum(None) | ||
Traceback (most recent call last): | ||
... | ||
TypeError: The grid does not contain the appropriate information | ||
>>> min_path_sum([[]]) | ||
Traceback (most recent call last): | ||
... | ||
TypeError: The grid does not contain the appropriate information | ||
""" | ||
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if not grid or not grid[0]: | ||
raise TypeError("The grid does not contain the appropriate information") | ||
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for cell_n in range(1, len(grid[0])): | ||
grid[0][cell_n] += grid[0][cell_n - 1] | ||
row_above = grid[0] | ||
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for row_n in range(1, len(grid)): | ||
current_row = grid[row_n] | ||
grid[row_n] = fill_row(current_row, row_above) | ||
row_above = grid[row_n] | ||
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return grid[-1][-1] | ||
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def fill_row(current_row: list, row_above: list) -> list: | ||
""" | ||
>>> fill_row([2, 2, 2], [1, 2, 3]) | ||
[3, 4, 5] | ||
""" | ||
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current_row[0] += row_above[0] | ||
for cell_n in range(1, len(current_row)): | ||
current_row[cell_n] += min(current_row[cell_n - 1], row_above[cell_n]) | ||
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return current_row | ||
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if __name__ == "__main__": | ||
import doctest | ||
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doctest.testmod() |