57 lines
1.4 KiB
Python
57 lines
1.4 KiB
Python
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# Given an infinite supply of:
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# - quarters
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# - dimes
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# - nickels
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# - pennies
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# Write a function to count the number of ways to make change of n.
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def get(table, row, col):
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"""
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Defensively get cell `row`, `col` from `table`.
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"""
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if row < 0 or row >= len(table):
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return 0
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if col < 0 or col >= len(table[0]):
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return 0
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return table[row][col]
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def print_table(table):
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print('\n'.join([
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','.join([str(col) for col in table[row]])
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for row in range(len(table))]))
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def init_table(rows=0, cols=0, default=0):
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result = []
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for row in range(rows):
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r = []
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for col in range(cols):
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r.append(default)
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result.append(r)
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return result
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def make_change(n):
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coins = [1, 5, 10, 25]
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table = init_table(rows=len(coins), cols=n)
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for row in range(len(table)):
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for col in range(len(table[row])):
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curr_coin = coins[row]
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curr_n = col + 1
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# a
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a = get(table, row - 1, col)
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# b
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b = get(table, row, curr_n - curr_coin - 1)
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# c
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c = 1 if curr_coin <= curr_n else 0
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# commit
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if curr_coin == curr_n:
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table[row][col] = a + c
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else:
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table[row][col] = a + b * c
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# debug
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print_table(table)
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print()
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return table[-1][-1]
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print(make_change(7))
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