New Go

BasicSyntax/prime/Circul.go

@@ -0,0 +1,46 @@
+package main
+
+import (
+	"fmt"
+	"math"
+)
+
+func circle(x1, y1, x2, y2 float64) float64 {
+	return math.Hypot(x2-x1, y2-y1)
+}
+
+func main() {
+	var n int
+	fmt.Scan(&n)
+
+	if n <= 0 {
+		fmt.Println("0.00")
+		return
+	}
+	if n == 1 {
+		fmt.Println("0.00")
+		return
+	}
+
+	var x1, y1 float64
+	fmt.Scan(&x1, &y1)
+
+	if n == 2 {
+		var x2, y2 float64
+		fmt.Scan(&x2, &y2)
+		fmt.Printf("%.2f\n", circle(x1, y1, x2, y2))
+		return
+	}
+
+	firstX, firstY := x1, y1
+	total := 0.0
+	for i := 1; i < n; i++ {
+		var x2, y2 float64
+		fmt.Scan(&x2, &y2)
+		total += circle(x1, y1, x2, y2)
+		x1, y1 = x2, y2
+	}
+	total += circle(x1, y1, firstX, firstY)
+
+	fmt.Printf("%.2f\n", total)
+}