Dijkstra

Dijkstra

 

 

 

#include <iostream>
#include <cstring>
using namespace std;

const int INF=0x3fffffff;

//最短路径
struct closedge{
    int adjvex;
    int lowcost;
    bool visited;
}closedge[105];
int am[105][105];
int n,m;
int start,end;//started ended

void printAm();
void printLowCost();

void init(){
    memset(am,127/3,sizeof(am));
    cin>>n>>m;
    int a,b,val;
    for(int i=1;i<=m;i++){
        cin>>a>>b>>val;
        am[a][b]=val;
    }
    cin>>start>>end;

    for(int i=1;i<=n;i++){
        closedge[i].adjvex=start;
        closedge[i].lowcost=am[start][i];
        closedge[i].visited=false;
    }
}

void dijkstra(){
    int k=n-1;
    while(k--){
        //找到最小
        printLowCost();
            int min=0x3fffffff,min_i=0;
            for(int i=1;i<=n;i++){
                if(!closedge[i].visited&&closedge[i].lowcost<min){
                    min=closedge[i].lowcost;
                    min_i=i;
                }
            }
            closedge[min_i].visited=true;
            //用这个最小的点去更新closedge
            for(int i=1;i<=n;i++){
                if(!closedge[i].visited){
                    if(closedge[i].lowcost>am[min_i][i]+min){
                        closedge[i].lowcost=am[min_i][i]+min;
                        closedge[i].adjvex=min_i;
                    }
                }
            }
    }
    cout<<closedge[end].lowcost<<endl;
}

void findWay(int end){
    if(end==start){
        cout<<start<<" ";
    }
    else{
        findWay(closedge[end].adjvex);
        cout<<end<<" ";
    }


}

int main() {
    freopen("src/in.txt","r",stdin);
    init();
    dijkstra();
    printAm();
    findWay(end);

    return 0;
}

void printLowCost(){
    for(int i=1;i<=n;i++){
        printf("%10d ",closedge[i].lowcost);
    }
    cout<<endl;
}

void printAm(){
    cout<<start<<" "<<end<<endl;
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n;j++){
            printf("%10d ",am[i][j]);
        }
        cout<<endl;
    }
}