How to Calculate the Sum of the Numbers in the Nth row of a Triangle in Golang

The challenge

Given the triangle of consecutive odd numbers:

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 ...
Code language: plaintext (plaintext)

Calculate the sum of the numbers in the nth row of this triangle (starting at index 1) e.g.: (Input –> Output)

1 --> 1 2 --> 3 + 5 = 8
Code language: plaintext (plaintext)

The solution in Golang

Option 1:

package solution func RowSumOddNumbers(n int) int { return n * n * n }
Code language: Go (go)

Option 2:

package solution import "math" func RowSumOddNumbers(n int) int { return int(math.Pow(float64(n), 3)) }
Code language: Go (go)

Option 3:

package solution func RowSumOddNumbers(n int) int { res := 0 for i := (n - 1) * n + 1; i < n * (n + 1); i = i + 2 { res = res + i } return res }
Code language: Go (go)

Test cases to validate our solution

package solution_test import ( . "github.com/onsi/ginkgo" . "github.com/onsi/gomega" ) var _ = Describe("Fixed tests", func() { It("Testing for 1", func() { Expect(RowSumOddNumbers(1)).To(Equal(1)) }) It("Testing for 2", func() { Expect(RowSumOddNumbers(2)).To(Equal(8)) }) It("Testing for 13", func() { Expect(RowSumOddNumbers(13)).To(Equal(2197)) }) It("Testing for 19", func() { Expect(RowSumOddNumbers(19)).To(Equal(6859)) }) It("Testing for 41", func() { Expect(RowSumOddNumbers(41)).To(Equal(68921)) }) It("Testing for 42", func() { Expect(RowSumOddNumbers(42)).To(Equal(74088)) }) It("Testing for 74", func() { Expect(RowSumOddNumbers(74)).To(Equal(405224)) }) It("Testing for 86", func() { Expect(RowSumOddNumbers(86)).To(Equal(636056)) }) It("Testing for 93", func() { Expect(RowSumOddNumbers(93)).To(Equal(804357)) }) It("Testing for 101", func() { Expect(RowSumOddNumbers(101)).To(Equal(1030301)) }) })
Code language: Go (go)
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