package main

import (
	"fmt"
	"math"
)

type point struct {
	x float64
	y float64
}

func (p *point) distance(other point) float64 {
	dx := p.x - other.x
	dy := p.y - other.y
	return math.Sqrt(dx*dx + dy*dy)
}

func (p *point) move(dx float64, dy float64) {
	p.x = p.x + dx
	p.y = p.y + dy
}

func main() {
	a := point{x: 0, y: 0}
	b := point{x: 3, y: 4}
	fmt.Println(a.distance(b)) // 5

	a.move(1, 1)
	fmt.Println(a.x, a.y)               // 1 1
	fmt.Printf("%.3f\n", a.distance(b)) // 3.606
}