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Special Number problem RRS feed

  • Question

  • The number 153 is a special number in that 153 = 1^3 + 5^3 + 3^3. There are three other numbers between 100 and 500 which are also special in the same way. Write a program which will enable you to find these numbers.
    Saturday, October 31, 2020 8:09 PM

All replies

  • solution:

    • Edited by Tryhest Sunday, November 1, 2020 7:42 AM
    • Proposed as answer by Nonki Takahashi Sunday, November 1, 2020 9:42 AM
    Sunday, November 1, 2020 7:41 AM
  • Hi emma5533, nice challenge problem.  My answer is:

    For n = 100 To 500
        x = Text.GetSubText(n, 1, 1)
        y = Text.GetSubText(n, 2, 1)
        z = Text.GetSubText(n, 3, 1)
        m = x * x * x + y * y * y + z * z * z
        If n = m Then
            TextWindow.WriteLine(n + " = " + x + "^3 + " + y + "^3 + " + z + "^3")
        EndIf
    EndFor

    And the result is:

    153 = 1^3 + 5^3 + 3^3
    370 = 3^3 + 7^3 + 0^3
    371 = 3^3 + 7^3 + 1^3
    407 = 4^3 + 0^3 + 7^3


    Nonki Takahashi

    Sunday, November 1, 2020 9:38 AM
  • Another program:

    For n = 100 To 500
        x3 = Math.Power(Math.Floor(n / 100), 3)
        y3 = Math.Power(Math.Floor(Math.Remainder(n, 100) / 10), 3)
        z3 = Math.Power(Math.Remainder(n, 10), 3)
        If n = x3 + y3 + z3 Then
            TextWindow.WriteLine(n + " = " + x3 + " + " + y3 + " + " + z3)
        EndIf
    EndFor

    The result:

    153 = 1 + 125 + 27
    370 = 27 + 343 + 0
    371 = 27 + 343 + 1
    407 = 64 + 0 + 343


    Nonki Takahashi

    Sunday, November 1, 2020 12:06 PM