2D Array Binary Search Golang

2d_array_binary_search_goland.go

package main

import (
	"errors"
	"fmt"
	"os"
)

func main() {
	array := [2][8]int{
		{17, 16, 15, 14, 13, 12, 11, 10},
		{9, 8, 7, 6, 5, 4, 3, 2},
	}
	x, y, err := find(array, 2)
	if err != nil {
		fmt.Println(err.Error())
		os.Exit(0)
	}

	fmt.Printf("\ninput array: %+v", array)
	fmt.Printf("\nfound value %d in position: %d,%d", array[x][y], x, y)
}

// find recieves a 2x8 array and a key integer to search.
func find(array [2][8]int, key int) (x int, y int, err error) {
	columnLength := len(array[0])
	low := 0
	high := columnLength - 1

	// As we only have two rows, we can figure out in
	// which row the number is positioned in O(1).
	if key < array[x][columnLength-1] {
		x++
	}

	// Then we do the binary search in only one row
	// in O(Log(n)).
	for low <= high {
		// In golang `/` on an int works the same way as `//`
		// in python.
		y = (low + high) / 2
		if array[x][y] == key {
			return x, y, nil
		} else if array[x][y] > key {
			low = y + 1
		} else {
			high = y - 1
		}
	}
	return 0, 0, errors.New("the number doesn't exist")
}