55 lines
957 B
Go
55 lines
957 B
Go
package main
|
|
|
|
import "math"
|
|
import "fmt"
|
|
|
|
type Shape interface {
|
|
area() float64
|
|
}
|
|
|
|
type Circle struct {
|
|
x, y, r float64
|
|
}
|
|
|
|
func (c *Circle) area() float64 {
|
|
return math.Pi * c.r * c.r
|
|
}
|
|
|
|
type Rectangle struct {
|
|
x1, y1, x2, y2 float64
|
|
}
|
|
|
|
func distance(x1, y1, x2, y2 float64) float64 {
|
|
a := x2 - x1
|
|
b := y2 - y1
|
|
return math.Sqrt(a*a + b*b)
|
|
}
|
|
|
|
func (r *Rectangle) area() float64 {
|
|
l := distance(r.x1, r.y1, r.x1, r.y2)
|
|
w := distance(r.x1, r.y1, r.x2, r.y1)
|
|
return l * w
|
|
}
|
|
|
|
func totalArea(shapes ...Shape) float64 {
|
|
var area float64
|
|
for _, s := range shapes {
|
|
area += s.area()
|
|
}
|
|
return area
|
|
}
|
|
|
|
func main() {
|
|
circle := Circle{x: 0, y: 3, r: 5}
|
|
rectangle := Rectangle{x1: 3, x2: 10, y1: 5, y2: 7}
|
|
|
|
area := 0.0
|
|
for _, s := range []Shape{&circle, &rectangle} {
|
|
area += s.area()
|
|
}
|
|
fmt.Println(area)
|
|
}
|
|
|
|
// todo: is this named wrong?
|
|
// todo: note about embedding access
|