Zoj 1450 Minimal Circle Minimum cover Circle

Title Link: http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemId=450

You is to write a program to find a circle which covers a set of points and have the minimal area. There'll be is no more than to points in one problem.

Test Instructions Description: Find a minimum circle that can be included in all two-dimensional coordinate points.

Algorithm analysis: The practice of minimum coverage circle.

1 //Minimum cover Circle2#include <iostream>3#include <cstdio>4#include <cstring>5#include <cstdlib>6#include <cmath>7#include <algorithm>8 #defineINF 0x7fffffff9 #defineExp 1E-10Ten #definePI 3.141592654 One using namespacestd; A Const intmaxn= ++Ten; - struct Point - { the     Doublex, y; -Point (Doublex=0,Doubley=0): X (x), Y (y) {} -}an[maxn],d;//d: Center coordinate of the smallest cover circle - DoubleR//radius of the minimum cover circle + typedef point Vector; -Vectoroperator+ (Vector a,vector B) {returnVector (a.x+b.x, a.y+b.y); } +Vectoroperator-(Vector a,vector B) {returnVector (a.x-b.x, a.y-b.y); } AVectoroperator* (Vector A,DoubleP) {returnVector (A.x*p, a.y*Q); } atVectoroperator/(Vector A,DoubleP) {returnVector (a.x/p, a.y/p); } - intDCMP (Doublex) - { -     if(Fabs (x) <exp)return 0; -     returnx<0? -1:1; - } in DoubleCross (Vector a,vector B) - { to     returna.x*b.y-b.x*a.y; + } - DoubleDist (Vector a,vector B) the { *     Doublex= (a.x-b.x) * (a.x-b.x); $     Doubley= (A.Y-B.Y) * (a.y-b.y);Panax Notoginseng     returnsqrt (x+y); - } the  + voidMinidiscwith2point (Point P,point Q,intN) A { theD= (P+Q)/2.0; +R=dist (P,Q)/2; -     intK; $     DoubleC1,c2,t1,t2,t3; $      for(k=1; k<=n; k++.) -     { -         if(Dist (d,an[k]) <=r)Continue; the         if(DCMP (p-an[k],q-an[k))! =0) -         {Wuyic1= (P.X*P.X+P.Y*P.Y-Q.X*Q.X-Q.Y*Q.Y)/2.0; theC2= (P.X*P.X+P.Y*P.Y-AN[K].X*AN[K].X-AN[K].Y*AN[K].Y)/2.0; -D.x= (c1* (P.Y-AN[K].Y)-c2* (P.Y-Q.Y))/((p.x-q.x) * (P.Y-AN[K].Y)-(p.x-an[k].x) * (p.y-q.y)); WuD.y= (c1* (p.x-an[k].x)-c2* (p.x-q.x))/((P.Y-Q.Y) * (p.x-an[k].x)-(P.Y-AN[K].Y) * (p.x-q.x)); -R=Dist (d,an[k]); About         } $         Else -         { -t1=Dist (p,q); -T2=Dist (q,an[k]); At3=Dist (p,an[k]); +             if(T1>=t2 && t1>=T3) the             { -D= (P+Q)/2.0; $R=dist (P,Q)/2.0; the             } the             Else if(T2>=t1 && t2>=T3) the             { theD= (AN[K]+Q)/2.0; -R=dist (AN[K],Q)/2.0; in             } the             Else the             { AboutD= (an[k]+p)/2.0; theR=dist (an[k],p)/2.0; the             } the         } +     } - } the voidMinidiscwithpoint (Point P,intN)Bayi { theD= (p+an[1])/2.0; theR=dist (p,an[1])/2.0; -     intJ; -      for(j=2; j<=n; j + +) the     { the         if(Dist (d,an[j]) <=r)Continue; the         Else the         { -Minidiscwith2point (p,an[j],j-1); the         } the     } the }94  the intMain () the { the     intN;98      while(SCANF ("%d", &n)!=eof &&N) About     { -          for(intI=1; i<=n; i++.)101         {102scanf"%LF%LF",&an[i].x,&an[i].y);103         }104         if(n==1) the         {106printf"%LF%lf\n", an[1].x,an[1].y);107             Continue;108         }109R=dist (an[1],an[2])/2.0; theD= (an[1]+an[2])/2.0;111          for(intI=3; i<=n; i++.) the         {113             if(Dist (d,an[i]) <=r)Continue; the             Else theMinidiscwithpoint (an[i],i-1); the         }117printf"%.2lf%.2lf%.2lf\n", d.x,d.y,r);118     }119     return 0; -}

Zoj 1450 Minimal Circle Minimum cover Circle