numberOfPossiblePathes.go

package main

import (
	"fmt"
	"os"
	"strconv"
)

func main() {
	m, n := sizeOfArea()

	// Well, we get width and height in human readable format, but we count from 0 :))
	fmt.Printf("Number of possible pathes from (0,0) to (%d,%d) is %d.\n", m, n, numberOfPath(m-1, n-1))
}

// Can you  make this code more efficient? You can find more information from any book about algorithm design or dynammic programming ;).
func numberOfPath(width, height int) int {
	if width == 0 && height == 0 {
		return 0
	}

	if width == 0 || height == 0 {
		return 1
	}

	return numberOfPath(width-1, height) + numberOfPath(width, height-1)
}

func sizeOfArea() (int, int) {
	if len(os.Args) > 1 {
		m, errm := strconv.Atoi(os.Args[1])
		var n int
		var errn error

		if len(os.Args) > 2 {
			n, errn = strconv.Atoi(os.Args[2])
		} else {
			n = m
		}

		if errm == nil && errn == nil {
			return m, n
		}
	}

	var m, n int
	fmt.Print("Please enter width of area >> ")
	fmt.Scanf("%d", &m)
	fmt.Print("Please enter height of area >> ")
	fmt.Scanf("%d", &n)

	return m, n
}