C++ Dijkstra算法 带路径输出 vector存图

该算法可以求任意两点之间的最短路,并且输出路径点。

#include <iostream>
#include <cstdio>
#include <vector>
#define Min(x,y) ( (x) < (y) ? (x) : (y) )
using namespace std;
const int maxn = 205;
const int INF = 0x3f3f3f3f;
int path[maxn];
struct Node
{
    int vex,weight;
    Node(int _vex = 0,int _weight = 0) : vex(_vex),weight(_weight){}
};
vector<Node> G[maxn];
bool intree[maxn];//判断是否已经加入最短路集合
int mindist[maxn],n,m;

void Init()
{
    for(int i = 0 ; i < maxn ; ++i){
        G[i].clear();
        mindist[i] = INF; //初始化为最大值
        intree[i] = false;
    }
}
int Dijkstra(int s,int e)
{
    int ans = 0;
    int vex,addNode,tempMin;//加入集合F中的节点

    intree[s] = true;//加入生成树
    for(unsigned int i = 0 ; i < G[s].size() ; ++i){
        vex = G[s][i].vex;
        mindist[vex] = Min(mindist[vex],G[s][i].weight);
        path[vex] = s;//vex点是由s点更新的
    }//寻找与当前节点相连的最小点
    mindist[s] = 0;//s到s的距离为自身
    for(int nodeNum = 1 ; nodeNum <= n - 1 ; ++nodeNum){//找到那个点把他加入
        tempMin = INF;
        for(int i = 0 ; i < n ; ++i){//编号0-n-1
            if(intree[i] == false && mindist[i] < tempMin){
                tempMin = mindist[i];
                addNode = i;
            }
        }
        intree[addNode] = true;//addNode 加入集合F
        for(unsigned int i = 0 ; i < G[addNode].size() ; ++i){//找到这个点的相邻点并且更新所有值
            vex = G[addNode][i].vex;
            if(intree[vex] == false && mindist[addNode] + G[addNode][i].weight < mindist[vex])//
                mindist[vex] = mindist[addNode] + G[addNode][i].weight;
                path[vex] = addNode;//更新之后的路径点
        }
    }
    return mindist[e];
}

void p()
{
    int tmp;

    while(!si.empty())si.pop();
    si.push(e);
    int ee = e;
    while(s!=e)
    {
        tmp=path[e];

        si.push(tmp);
        e= tmp;
    }
        if(!outfile){
          cout << "Unable to open otfile";
          exit(1);
        }
        outfile<<s<<"到"<<ee<<"所经历的点为:"<<endl;
        int cnt=0;
    while(!si.empty())
    {
       cout<<' '<<si.top();
       si.pop();
    }
    cout<<endl;
}
int main()
{

    int v1,v2,weight,s,e;
    while(scanf("%d%d",&n,&m) != EOF)//n个节点,m条边
    {
        Init();//初始化函数
        for(int i = 0 ; i < m ; i++){
            scanf("%d%d%d",&v1,&v2,&weight);//无向图V1与V2相连,所以V2与V1相连,weight为两点之间的长度
            G[v1].push_back(Node(v2,weight));
            G[v2].push_back(Node(v1,weight));
        }
        scanf("%d%d",&s,&e);//s为起始点,e为终点
        int ans = Dijkstra(s,e);
        if(ans == INF)
            printf("%d\n",-1);
        else
            printf("%d\n",ans);
    }
    return 0;
}

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转载自blog.csdn.net/qq_35736364/article/details/89375811