HDU 1162 Eddy ' s picture (minimum spanning tree) (Java edition)

Eddy ' s picture

Title Link: http://acm.hdu.edu.cn/showproblem.php?pid=1162

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Main topic:

Give you n points, the shortest total distance to connect the n points together.

Ideas:

Assume that there is a path between every 22 points to find the smallest spanning tree.

AC Code: (Java)

1 ImportJava.util.Scanner;2 Importjava.math.*;3  Public classMain {4      Public Static Final intMAXN = 110;5      Public Static DoubleMp[][] =New Double[MAXN][MAXN];6      Public StaticPoint p[] =NewPOINT[MAXN];7      Public Static intN;8      Public StaticString answer =NewString ();9      Public StaticScanner SCN =NewScanner (system.in);Ten      Public Static voidMain (string[] args) { One          for(inti = 0; i < MAXN; i++){ AP[i] =NewPoint (); -         } -          while(Scn.hasnext ()) { then =scn.nextint (); - Foundmap (); -Answer = String.Format ("%.2f", Prim ()); - System.out.println (answer); +         } -System.exit (0); +     } A      Public Static BooleanFoundmap () { at         Doublex, y; -          for(inti = 0; I < n; i++) { -x =scn.nextdouble (); -y =scn.nextdouble (); - p[i].setpoint (x, y); -}//Found points in          for(inti = 0; I < n; i++) -              for(intj = 0; J < N; J + +) to                 if(I! =j) +MP[I][J] =Point.getdistencs (P[i], p[j]); -         //Found Map the         return true; *     } $      Public Static DoublePrim () {Panax Notoginseng         inttempi; -         DoubleTempclos; the         Double[] Closedge =New Double[MAXN]; +         Doublesum = 0.0; A         //Init Closeedge theClosedge[0] = 0.0; +          for(inti = 1; I < n; i++) { -Closedge[i] = mp[0][i]; $         } $         //Find n-1 Edge -          for(inti = 1; I < n; i++) { -Tempi =-1; theTempclos =-1.0; -              for(intj = 0; J < N; J + +) {Wuyi                 if(Closedge[j]! = 0.0 && (Tempclos = = -1.0 | | closedge[j] <Tempclos)) { theTempclos =Closedge[j]; -Tempi =J; Wu                 } -             } AboutSum + =Tempclos; $Closedge[tempi] = 0; -              for(intj = 0; J < N; J + +) { -                 if(J! = Tempi && Closedge[j] >Mp[tempi][j]) { -CLOSEDGE[J] =Mp[tempi][j]; A                 } +             } the         } -         returnsum; $     } the } the classPoint { //has been down as a dot class can not look at.  the     Private Doublex; the     Private Doubley; -      PublicPoint (DoubleXDoubley) { in          This. x =x; the          This. y =y; the     } About      PublicPoint () { thex = 0.0; they = 0.0; the     } +      Public voidSetPoint (DoubleXDoubleY) { -          This. x =X; the          This. y =Y;Bayi     } the      Public DoubleGetX () { the         returnx; -     } -      Public DoubleGetY () { the         returny; the     } the      Public Static DoubleGetdistencs (Point p1,point p2) { the         returnMath.sqrt (Math.pow (P1.getx ()-P2.getx (), 2.0) + Math.pow (p1.gety ()-p2.gety (), 2.0)); -     } the}

2017-07-23 13:07:39

HDU 1162 Eddy ' s picture (minimum spanning tree) (Java edition)