65 lines
1.3 KiB
C++
65 lines
1.3 KiB
C++
#include <iostream>
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#include <cmath>
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using namespace std;
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#define max(a,b) ((a)>=(b)?(a):(b))
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const int maxn = 50000;
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struct node
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{
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double x, y;
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}pt[maxn+5];
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bool set(double &tl, double &tr, double cl, double cr)
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{
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if (cl>tr || tl>cr) return false;
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if (tr>cr) tr = cr;
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if (tl<cl) tl = cl;
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return true;
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}
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bool ok(double r, int n, double &p)
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{
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int i;
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double r2 = r*r;
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double td, tl, tr;
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td = sqrt(r2-pt[0].y*pt[0].y);
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tl = pt[0].x - td;
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tr = pt[0].x + td;
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for (i=1; i<n; i++)
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{
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td = sqrt(r2-pt[i].y*pt[i].y);
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if (!set(tl, tr, pt[i].x-td, pt[i].x+td))
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return false;
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}
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p = (tl+tr)/2;
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return true;
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}
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void solve(int n, double &p, double &d)
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{
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double low = 0, high = 3e5;
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int i;
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for (i=0; i<n; i++) low = max(low, fabs(pt[i].y));
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double mid;
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while(fabs(high-low)>1e-9)
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{
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mid = (low+high)/2;
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if (ok(mid, n, p))
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{
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d = mid;
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high = mid;
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}
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else low = mid;
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}
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}
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int main()
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{
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int n;
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int i;
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double p, d;
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while(scanf("%d", &n)!=EOF)
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{
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if (n==0) break;
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for (i=0; i<n; i++) scanf("%lf %lf", &pt[i].x, &pt[i].y);
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solve(n, p, d);
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printf("%.9lf %.9lf\n", p, d);
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}
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return 0;
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}
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