Prim 算法

按照课件的思路整合的代码，哈哈

#include<iostream>#include<cstdio>#include<cstdlib>using namespace std;#define MaxValue 32700const int NumEdges = 50;         //边条数const int NumVertices = 10;    //顶点个数typedef char VertexData;        //顶点数据类型typedef int EdgeData;              //边上权值类型typedef struct {    //VertexData vexList[NumVertices];   //顶点表    EdgeData Edge[NumVertices][NumVertices];    //邻接矩阵, 可视为边之间的关系    int n, e;    //图中当前的顶点个数与边数} MTGraph;typedef struct {    int head,tail;    int cost;} MST;MST T[100];void Prim ( MTGraph G, MST T[] ,int u ) {    double  lowcost[G.n];    int nearvex[G.n];    for ( int i = 0; i < G.n; i++ ) {        lowcost[i] = G.Edge[u][i];   //Vu到各点代价        nearvex[i] = u;                 //及最短带权路径    }    nearvex[u] = -1;        //加到生成树顶点集合    int k = 0;            //存放最小生成树结点的变量    for ( int i = 0; i < G.n; i++ ) {        if ( i != u ) {     //循环n-1次, 加入n-1条边            EdgeData min = MaxValue;            int v = 0;            for ( int j = 0; j < G.n; j++ ) {                if ( nearvex[j] != -1 &&     // =-1不参选                        lowcost[j] < min ) {                    v = j;                    min = lowcost[j];                }                //求生成树外顶点到生成树内顶点具有最                //小权值的边, v是当前具最小权值的边            }            if ( v ) {     //v=0表示再也找不到要求顶点                T[k].tail = nearvex[v]; //选边加入生成树                T[k].head = v;                T[k++].cost = lowcost[v];                nearvex[v] = -1;  //该边加入生成树标记                for ( int j = 0; j < G.n; j++ )                    if ( nearvex[j] != -1 &&                            G.Edge[v][j] < lowcost[j] ) {                        lowcost[j] = G.Edge[v][j];     //修改                        nearvex[j] = v;                    }            }        }     //循环n-1次, 加入n-1条边    }}int main() {    MTGraph G;    int s,t,path;    cout<<"请输入顶点个数"<<endl;    cin>>G.n;    cout<<"请输入边数"<<endl;    cin>>G.e;    for(int i=0; i<G.n; i++) {        for(int j=0; j<G.n; j++) {            if(i==j) G.Edge[i][j]=0;            else G.Edge[i][j]=MaxValue;        }    }    cout<<"请输入各边权值"<<endl;    for(int i=1; i<=G.e; i++) {        cin>>s>>t>>path;        G.Edge[s][t]=G.Edge[t][s]=path;    }    Prim(G,T,0);    cout<<endl;    for(int i=0;i<G.n-1;i++){        cout<<T[i].head<<" "<<T[i].tail<<" "<<T[i].cost<<endl;    }     return 0;}/*0 1 281 2 162 3 123 4 224 5 255 0 104 6 243 6 181 6 14*/