#include<stdio.h>#include<string.h>#include<math.h>#define MAXD 210#define zero 1e-8#define INF 2000struct point{ double x, y;}p[MAXD], wa[MAXD], wb[MAXD], *a, *b;int N, R, na, nb;double det(double x1, double y1, double x2, double y2){ return x1 * y2 - x2 * y1;}int dcmp(double x){ return fabs(x) < zero ? 0 : (x < 0 ? -1 : 1);}double sqr(double x){ return x * x;}void init(){ int i, j, k; for(i = 0; i < N; i ++) scanf("%lf%lf", &p[i].x, &p[i].y); p[N] = p[0];}void add(double x, double y){ b[nb].x = x, b[nb].y = y; ++ nb;}void cut(int k){ int i, j; double x, y, t1, t2, dx, dy; t1 = sqrt(sqr(p[k + 1].x - p[k].x) + sqr(p[k + 1].y - p[k].y)); dx = (p[k].y - p[k + 1].y) / t1 * R; dy = (p[k + 1].x - p[k].x) / t1 * R; point *t; nb = 0; for(i = 0; i < na; i ++) { t1 = det(p[k + 1].x - p[k].x, p[k + 1].y - p[k].y, a[i].x + dx - p[k].x, a[i].y + dy - p[k].y); t2 = det(p[k + 1].x - p[k].x, p[k + 1].y - p[k].y, a[i + 1].x + dx - p[k].x, a[i + 1].y + dy - p[k].y); if(dcmp(t1) <= 0) add(a[i].x, a[i].y); if(dcmp(t1) * dcmp(t2) < 0) { x = (fabs(t2) * a[i].x + fabs(t1) * a[i + 1].x) / (fabs(t1) + fabs(t2)); y = (fabs(t2) * a[i].y + fabs(t1) * a[i + 1].y) / (fabs(t1) + fabs(t2)); add(x, y); } } t = a, a = b, b = t; na = nb; a[na] = a[0];}void solve(){ int i, j, k; double t, max, x1, y1, x2, y2; a = wa, b = wb; na = 4; a[0].x = -INF, a[0].y = -INF, a[1].x = -INF, a[1].y = INF, a[2].x = INF, a[2].y = INF, a[3].x = INF, a[3].y = -INF; a[na] = a[0]; for(i = 0; i < N; i ++) cut(i); max = -1.0; for(i = 0; i < na; i ++) for(j = i; j < na; j ++) { t = sqrt(sqr(a[i].x - a[j].x) + sqr(a[i].y - a[j].y)); if(dcmp(t - max) > 0) { x1 = a[i].x, y1 = a[i].y; x2 = a[j].x, y2 = a[j].y; max = t; } } printf("%.5lf %.5lf %.5lf %.5lfn", x1, y1, x2, y2);}int main(){ while(scanf("%d%d", &N, &R) == 2) { init(); solve(); } return 0;}
