```go
package main
import (
"bufio"
"fmt"
"math"
"os"
"sort"
)
type Point struct {
x, y int64
}
func nextInt(scanner *bufio.Scanner) int64 {
scanner.Scan()
res := int64(0)
sign := int64(1)
for _, b := range scanner.Bytes() {
if b == '-' {
sign = -1
} else if b >= '0' && b <= '9' {
res = res*10 + int64(b-'0')
}
}
return res * sign
}
func main() {
scanner := bufio.NewScanner(os.Stdin)
scanner.Split(bufio.ScanWords)
if !scanner.Scan() {
return
}
N := 0
for _, b := range scanner.Bytes() {
if b >= '0' && b <= '9' {
N = N*10 + int(b-'0')
}
}
pts := make([]Point, N)
for i := 0; i < N; i++ {
pts[i].x = nextInt(scanner)
pts[i].y = nextInt(scanner)
}
area2 := int64(0)
for i := 0; i < N; i++ {
area2 += pts[i].x*pts[(i+1)%N].y - pts[(i+1)%N].x*pts[i].y
}
if area2 < 0 {
for i, j := 0, N-1; i < j; i, j = i+1, j-1 {
pts[i], pts[j] = pts[j], pts[i]
}
}
pref := make([]int64, N+1)
for i := 0; i < N; i++ {
pref[i+1] = pref[i] + (pts[i].x*pts[(i+1)%N].y - pts[(i+1)%N].x*pts[i].y)
}
angles := make([]float64, 2*N)
for i := 0; i < 2*N; i++ {
u1 := float64(pts[i%N].x)
v1 := float64(pts[i%N].y)
u2 := float64(pts[(i+1)%N].x)
v2 := float64(pts[(i+1)%N].y)
dx := u2 - u1
dy := v2 - v1
ang := math.Atan2(dy, dx) - math.Pi/2
for ang < 0 {
ang += 2 * math.Pi
}
for ang >= 2*math.Pi {
ang -= 2 * math.Pi
}
angles[i] = ang
}
for i := 1; i < 2*N; i++ {
for angles[i] < angles[i-1] {
angles[i] += 2 * math.Pi
}
}
getExtremeVertex := func(beta float64) int {
for beta < angles[0] {
beta += 2 * math.Pi
}
for beta >= angles[0]+2*math.Pi {
beta -= 2 * math.Pi
}
idx := sort.Search(2*N, func(i int) bool {
return angles[i] >= beta
})
return idx % N
}
getCapArea := func(L, B int) float64 {
var pathArea2 int64
if L <= B {
pathArea2 = pref[B] - pref[L]
} else {
pathArea2 = pref[N] - pref[L] + pref[B]
}
cross2 := pts[B].x*pts[L].y - pts[L].x*pts[B].y
return float64(pathArea2+cross2) * 0.5
}
computeCornerArea := func(C, S float64) float64 {
betaL := math.Atan2(S, -C)
L := getExtremeVertex(betaL)
betaB := math.Atan2(-C, -S)
B := getExtremeVertex(betaB)
XL := float64(pts[L].x)*C - float64(pts[L].y)*S
YL := float64(pts[L].x)*S + float64(pts[L].y)*C
XB := float64(pts[B].x)*C - float64(pts[B].y)*S
YB := float64(pts[B].x)*S + float64(pts[B].y)*C
capArea := getCapArea(L, B)
area := 0.5*(XB-XL)*(YL-YB) - capArea
if area < 0 {
area = 0
}
return area
}
minCornerArea := math.Inf(1)
for i := 0; i < N; i++ {
dx := float64(pts[(i+1)%N].x - pts[i].x)
dy := float64(pts[(i+1)%N].y - pts[i].y)
D := math.Hypot(dx, dy)
C1, S1 := dx/D, -dy/D
area1 := computeCornerArea(C1, S1)
if area1 < minCornerArea {
minCornerArea = area1
}
C2, S2 := -dy/D, -dx/D
area2 := computeCornerArea(C2, S2)
if area2 < minCornerArea {
minCornerArea = area2
}
}
fmt.Printf("%.10f\n", minCornerArea)
}
```