最小生成樹（不記錄路徑）

/*********************************************
*@time 2016/08/10 21:46
*@description prim算法求最小生成樹
*@author dzq
**********************************************/
#include<cstdio>
#include<iostream>
#include<cstring>
#include<algorithm>
#define INF 1<<30
using namespace std;
/****************************************************
*@函數名           prim
*@parameter        int *route   將路徑保存在一個一維數組中
*@parameter        num_Of_Node  圖中節點的數量
*@返回值           int          最小生成樹的大小
*@description       prim算法求最小生成樹;每找到一個離生成樹的點，就將其加入最小生成樹（visit=true）,再更新其他節點到樹的距離
************************************************************/
int prim(int *route,int num_Of_Node)
{
    int dis[num_Of_Node];
    bool visit[num_Of_Node];
    int shortest_Distance=0;
    memset(visit,0,sizeof(visit));

    int last_Add_Node=0;//離生成樹最近的點
    int nearest_Distance=INF;
    for(int i=0;i<num_Of_Node;i++)
    {
        dis[i]=INF;
    }

    visit[0]=true;
    for(int i=1;i<num_Of_Node;i++)
    {
      //  printf("last_Add_Node=%c\n",last_Add_Node+'A');
        int nearest_Node;
        nearest_Distance=INF;
        for(int j=0;j<num_Of_Node;j++)//根據nearest_Distance更新不在最小樹的點到最小數的距離
        {
            if(!visit[j]&&dis[j]>route[last_Add_Node*num_Of_Node+j])//route[last_Add_Node*m+j]=route[last_Add_Node][i]
            {
               // printf("%d %d %d\n",last_Add_Node,i,route[last_Add_Node*num_Of_Node+j]);
                dis[j]=route[last_Add_Node*num_Of_Node+j];//更新最小生成樹的總距離
                if(dis[j]==0) printf("%d %d %d\n",last_Add_Node,i,route[last_Add_Node*num_Of_Node+j]);
            }
        }

        for(int j=0;j<num_Of_Node;j++)//找到離最小樹最近的點
        {
            if(!visit[j]&&nearest_Distance>dis[j])
            {
                nearest_Distance=dis[j];
                nearest_Node=j;
            }
        }

        shortest_Distance+=nearest_Distance;
        last_Add_Node=nearest_Node;
        visit[last_Add_Node]=true;
        printf("last_Add_Node=%c,nearest_Distance=%d\n",last_Add_Node+'A',nearest_Distance);
        printf("shortest_Distance=%d\n",shortest_Distance);
    }
    return shortest_Distance;
}
int main()
{
    int num_Of_Node;
    int* route;
    printf("Please input the num of node\n");
    scanf("%d",&num_Of_Node);
    route=(int *)malloc( num_Of_Node*num_Of_Node*sizeof(int));
    for(int i=0;i<num_Of_Node;i++)
    {
        for(int j=0;j<num_Of_Node;j++)
        {
           route[i*num_Of_Node+j]=INF;
        }
    }
    printf("Please input all node and dis\n");
    int route_Begin_Node;
    int route_End_Node;
    int distance;
    while(scanf("%d %d %d",&route_Begin_Node,&route_End_Node,&distance))
    {
        if(route_Begin_Node==route_End_Node) break;
        route[route_Begin_Node*num_Of_Node+route_End_Node]=distance;
        route[route_End_Node*num_Of_Node+route_Begin_Node]=distance;//無向圖
    }

    int shortest_Distance=prim(route,num_Of_Node);
    printf("The shortest_Distance is %d",shortest_Distance);
}
/*************
用例
7
0 1 7
0 3 5
1 2 8
1 3 9
1 4 7
2 4 5
3 4 15
3 5 6
4 5 8
4 6 9
5 6 11
0 0 0
*/