图的最小生成树：Prim算法实现

/*
*无向图查找最小树：Prim算法
*不断找已知顶点邻接边中的最小值，在不形成环的前提下，加入边
*----- By F8Master
*/

#include "Graphmtx.h"
#include<iostream>
#include<vector>
using namespace std;

struct EdgeByInt
{
    int v1,v2;
    EdgeByInt(){};
    EdgeByInt (int v11,int v22){
        v1 = v11;
        v2 = v22;
    }
};

template<class T ,class E>
void Prim(Graphmtx<T,E> &G,vector<EdgeByInt> &v)//参数分别为图G，存储最小树的边的vector v
{
    int numV = G.NumberOfVertices();//顶点数
    int *setV = new int[numV];//表明所在集合的
    for(int i = 0;i<numV;i++)//setV初始化为本身，当已经访问过之后，会更改其值为-1
        setV[i] = i;
    v.clear();
    vector<int> vvertex(numV);//存已分配好了的点
    vvertex.push_back(0);
    setV[0] = -1;//凡是分配好的点均被设置为-1，以示区别
    
    int j = 0;//找到的边的数目
    while( j < numV - 1)
    {
        E min = INF;
        int left = -1;
        int right = -1;
        for(int n = 0;n<vvertex.size();n++)//找到已知集里面点的邻接最近点
        {
            for (int m = 0;m<numV;m++)
            {
                if(m!=n && setV[m] != -1 &&G.getWeight(vvertex[n],m)<min )
                {
                    min = G.getWeight(vvertex[n],m);
                    left = vvertex[n];
                    right = m;
                }
            }
        }
        setV[right] = -1;
        vvertex.push_back(right);
        EdgeByInt temp(left,right);
        v.push_back(temp);
        j++;
    }
}

template <class T ,class E>
void printMinTree(Graphmtx<T,E> & G,vector<EdgeByInt> &v)
{
    int size = v.size();
    EdgeByInt  temp;
    int left,right;
    for(int i = 0;i<size;i++)
    {
        temp = v[i];
        left = v[i].v1;
        right = v[i].v2;
        cout<<"("<<G.getValue(left)<<" , "<<G.getValue(right)<<")"<<endl;
    }
};
//测试程序
void test_Prim()
{
    Graphmtx<char,int> G ;
    G.inputGraph();
    vector<EdgeByInt> v(G.NumberOfEdges()-1);
    Prim(G,v);
    printMinTree(G,v);
}