Sum of Squares

main.go

package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
)

func main() {
	Scanner := bufio.NewScanner(os.Stdin)

	var (
		sum            []int
		rowInput       int
		numOfTestCases int
	)

	nyanCatInit(rowInput, numOfTestCases, sum, Scanner)
}

func nyanCatInit(iterationRow int, numOfTestCases int, sum []int, Scanner *bufio.Scanner) {
	Scanner.Scan()
	input := Scanner.Text()

	updateTestCasesCount(&numOfTestCases, iterationRow, input)

	//get remaining input [1:] from row
	rest := strings.Split(input, " ")

	//ignore first 2 rows input
	if iterationRow > 0 && iterationRow%2 == 0 {
		sumSquareOfRow := sumOfSquares(rest)
		sum = append(sum, sumSquareOfRow)
	}

	if numOfTestCases == iterationRow/2 {
		printRow(sum) //finally print all & exit
		return
	}

	// else we keep running nyan-cat
	iterationRow += 1
	nyanCatInit(iterationRow, numOfTestCases, sum, Scanner)
}

func printRow(sum []int) {
	fmt.Println(sum[0])
	rest := sum[1:]
	if len(rest) == 0 {
		return
	}
	printRow(rest)
}

func sumOfSquares(numArr []string) int {
	i, err := strconv.Atoi(numArr[0])
	checkError(err)
	rest := numArr[1:]
	square := i * i

	// negative & last number
	if i < 0 && len(rest) == 0 {
		return square
	}

	// negative & not last number
	if i < 0 && len(rest) > 0 {
		return sumOfSquares(rest)
	}

	// last man standing
	if i >= 0 && len(rest) == 0 {
		return square
	}

	return square + sumOfSquares(rest)
}

func updateTestCasesCount(testCases *int, iterationRow int, input string) {
	if iterationRow == 0 {
		firstInput, err := strconv.Atoi(input)
		checkError(err)
		if firstInput == 0 {
			os.Exit(0) //we break if zero
		}

		*testCases = firstInput
	}
}

//Error checking
func checkError(err error) {
	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}
}