最小生成树之prime算法

public class Prime {
    public static void main(String[] args) {
        //路径矩阵
        int arcs[][] = {{-1,6,1,5,-1,-1},{6,-1,5,-1,3,-1},{1,5,-1,5,6,4},{5,-1,5,-1,-1,2},{-1,3,6,-1,-1,6},{-1,-1,4,2,6,-1}};
        //[i][0]保存i到那个顶点    [i][1]保存这两个顶点之间的距离，如果为0则代表顶点i已经加入到了最小生成树里，如果为-1则这两个顶点之间不存在直接相连的边
        int closedge[][] = new int[arcs.length][2];
        int start = 0;//初始化顶点为0
        closedge[start][1] = 0;//顶点0已经被加入到最小生成树集合U
        for(int i=0;i<arcs.length;i++){//初始化其他顶点到顶点0的状态
            if(i!=start){
                closedge[i][0] = start; //顶点i到顶点start(0)
                closedge[i][1] = arcs[start][i]; //顶点i和顶点0之间的距离
            }
        }
        for(int i=0;i<arcs.length-1;i++){
            int k = 0; int min = Integer.MAX_VALUE;
            for(int j=0;j<arcs.length;j++){//循环closedge 找出距离最短的那一条
                if(closedge[j][1] < min && closedge[j][1] != 0 && closedge[j][1] != -1){
                    min = closedge[j][1];
                    k = j;//记录下来是到哪个顶点最小
                }
            }
            closedge[k][1] = 0;//然后将该顶点加入到集合U中
            System.out.println(closedge[k][0]+1 +"->" + (k+1));//输出从那条边
            for(int a=0;a<arcs.length;a++){ //以下一个顶点为起点 重新计算距离
                 if(arcs[k][a]!=-1&& closedge[a][1] !=0){  
                    closedge[a][0] = k;
                    closedge[a][1] = arcs[k][a];
                }
            }
        }
    }
}