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https://github.com/TheAlgorithms/Ruby
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57 lines
1.4 KiB
Ruby
57 lines
1.4 KiB
Ruby
# A ruby program to determine whether a given number is an Armstrong number
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# Wiki url: https://en.wikipedia.org/wiki/Narcissistic_number
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# other resources: https://pages.mtu.edu/~shene/COURSES/cs201/NOTES/chap04/arms.html
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#
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# Examples: -> 153 = (1 * 1 * 1) + (5 * 5 * 5) + (3 * 3 * 3) [Armstrong number] and -> 125 != (1 * 1 * 1) + (2 * 2 * 2) + (5 * 5 * 5)
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# -> 1634 = (1 * 1 * 1 * 1) + (6 * 6 * 6 * 6) + (3 * 3 * 3 * 3) + (4 * 4 * 4 * 4)
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#
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def armstrong_number(number)
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num = number
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sum = 0
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len = number.digits.count
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while(number != 0)
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remainder = number % 10
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sum += remainder ** len
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number /= 10
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end
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if num == sum
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"The number #{num} is an Armstrong number."
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else
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"The number #{num} is not an Armstrong number."
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end
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rescue
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"Error: Please provide number only!"
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end
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#
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# Valid inputs
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#
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puts armstrong_number(153)
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# The number 153 is an Armstrong number.
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puts armstrong_number(0)
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# The number 0 is an Armstrong number.
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puts armstrong_number(370)
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# The number 370 is an Armstrong number.
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puts armstrong_number(10)
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# The number 10 is not an Armstrong number.
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puts armstrong_number(1634)
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# The number 1634 is an Armstrong number.
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puts armstrong_number(123)
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# The number 123 is not an Armstrong number.
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#
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# Invalid inputs
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#
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puts armstrong_number("153")
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# Error: Please provide number only!
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puts armstrong_number("a")
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# Error: Please provide number only!
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