最小生成树（城市之间的最短距离）

来源：互联网发布：故宫淘宝营销策略分析编辑：程序博客网时间：2024/06/06 02:33
package coding;import java.util.Scanner;/* * 最小生成树求解城市间的最短距离 */class GraphMatrix1{    static final int MaxNum=20;    char[] Vertex=new char[MaxNum];    int GType;    int VertexNum;    int EdgeNum;    int [][] EdgeWeight=new int [MaxNum][MaxNum];    int [] isTra=new int[MaxNum];}public class cha07_minTree {    static final int MaxValue=65535;    static final int USED=0;    static final int Nol=-1;    static Scanner input =new Scanner(System.in);    static void CreateGraph(GraphMatrix1 GM){        int i,j,k;        int weight;        char EstartV,EendV;        System.out.printf("输入图中各顶点的信息：\n");        for(i=0;i<GM.VertexNum;i++){            System.out.printf("第%d个顶点：",i+1);            GM.Vertex[i]=(input.next().toCharArray()[0]);        }        System.out.printf("输入构成各边的顶点及权值：\n");        for(k=0;k<GM.EdgeNum;k++){            System.out.printf("第%d条边:",k+1);            EstartV=input.next().charAt(0);            EendV=input.next().charAt(0);            weight=input.nextInt();            for(i=0;EstartV!=GM.Vertex[i];i++);            for(j=0;EendV!=GM.Vertex[j];j++);            GM.EdgeWeight[i][j]=weight;            if(GM.GType==0){                GM.EdgeWeight[i][j]=weight;            }        }        }    static void clearGraph(GraphMatrix1 GM){        int i,j;        for(i=0;i<GM.VertexNum;i++){            for(j=0;j<GM.VertexNum;j++){                GM.EdgeWeight[i][j]=MaxValue;            }        }    }    static void OutGraph(GraphMatrix1 GM){        int i,j;        for(j=0;j<GM.VertexNum;j++){            System.out.printf("\t%c",GM.Vertex[j]);        }        System.out.println();        for(i=0;i<GM.VertexNum;i++){            System.out.printf("%c",GM.Vertex[i]);            for(j=0;j<GM.VertexNum;j++){                if(GM.EdgeWeight[i][j]==MaxValue){                    System.out.printf("\tZ");                }                else{                    System.out.printf("\t%d",GM.EdgeWeight[i][j]);                }            }            System.out.println();        }    }    static void primGraph(GraphMatrix1 GM){        int i,j,k,min,sum;        int[]weight=new int[GraphMatrix1.MaxNum];        char[]vtempx=new char[GraphMatrix1.MaxNum];        sum=0;        for(i=1;i<GM.VertexNum;i++){            weight[i]=GM.EdgeWeight[0][i];            if(weight[i]==MaxValue){                vtempx[i]=(char)Nol;            }else{                vtempx[i]=GM.Vertex[0];            }        }        vtempx[0]=USED;        weight[0]=MaxValue;        for(i=1;i<GM.VertexNum;i++){            min=weight[0];            k=i;            for(j=0;j<GM.VertexNum;j++){                if(weight[j]<min&&vtempx[j]>0){                    min=weight[j];                    k=j;                }            }            sum+=min;            System.out.printf("(%c,%c),",vtempx[k],GM.Vertex[k]);            vtempx[k]=USED;            weight[k]=MaxValue;            for(j=0;j<GM.VertexNum;j++){                if(GM.EdgeWeight[k][j]<weight[j]&&vtempx[j]!=0){                    weight[j]=GM.EdgeWeight[k][j];                    vtempx[j]=GM.Vertex[k];                }            }        }        System.out.println("最小生成树的总权值："+sum);    }    public static void main(String[] args) {        // TODO Auto-generated method stub    GraphMatrix1 GM=new GraphMatrix1();    char again;    String go;    System.out.println("需找最小生成树");    do{        System.out.printf("请输入生成图的类型 :\n");        GM.GType=input.nextInt();        System.out.printf("输入图的顶点数量：\n");        GM.VertexNum=input.nextInt();        System.out.printf("输入图的边数量：\n");        GM.EdgeNum=input.nextInt();        clearGraph(GM);        CreateGraph(GM);        System.out.println("最小生成树的边为：");        primGraph(GM);        System.out.println("继续玩吗?(y/n)");        go=input.next();    }while(go.equalsIgnoreCase("y"));    System.out.println("游戏结束！");    }}
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