HENNGE GoLang Code Challenge

mission1.go

package main

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

func main() {
	var (
		scanner *bufio.Scanner;
		iterations int;
		calculated_values []int;
	)

	scanner = bufio.NewScanner(os.Stdin);
	iterations = read_iterations(scanner);
	calculated_values = make([]int, iterations);

	process_numbers_recursive(scanner, &calculated_values, 0, iterations);
	print_values_recursive(calculated_values);
	os.Exit(0);
}

func read_iterations(scanner *bufio.Scanner) int {
	scanner.Scan();
	n, err := strconv.Atoi(scanner.Text());
	if err != nil {
		log.Fatal(err);
	}
	return n;
}

func process_numbers_recursive(scanner *bufio.Scanner, calculated_values *[]int, iteration int, iterations int) {
  if ( iteration > (iterations - 1) ) { return; }
	
	//Skip amount of numbers
	scanner.Scan();

	//String split the actual numbers
	scanner.Scan();
	numbers_slice := strings.Split(scanner.Text(), " ");
	solution := calculate_square_recurisve(numbers_slice);

	(*calculated_values)[iteration] = solution;
	
	process_numbers_recursive(scanner, calculated_values, iteration + 1, iterations);
}

func calculate_square_recurisve(number_slice []string) int {
	if ( len(number_slice) <= 0 ) { return 0; }

	number, err := strconv.Atoi(number_slice[0]);
	if ( err != nil ) {
		log.Fatal(err);
	}

	if ( number <= 0 ) {
		return calculate_square_recurisve(number_slice[1:])
	}
	
	return (number * number) + calculate_square_recurisve(number_slice[1:]);
}

func print_values_recursive(calculated_values []int) {
	if ( len(calculated_values) < 1 ) { return; }
	fmt.Println( calculated_values[0] );
	print_values_recursive( calculated_values[1:] );
}

This was the code used to get me an interview at the Japanese company HENNGE, for a Back-End Software Developer.

The request was to make a script/program that handled an input stream of numbers and (ignoring negatives) square them, and add each together without using a for loop.

e.g.

2 (iterations)
4 (first iteration has 4 numbers)
5 32 -5 44 (4 numbers)
5 (second iteration has 5 numbers)
9 -1 81 72 -33 (5 numbers)

would return

2985
11826