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