PTA 甲级 1030 Travel Plan

题目链接

做了好几道这类题了，dijkstra单源最短路径一气呵成

#include
#include
#include
#define MAXN 510
using namespace std;
 
int road[MAXN][MAXN];
int cost[MAXN][MAXN];
int vis[MAXN],roadMin[MAXN],costMin[MAXN];
vector<int> pre[MAXN];
const int inf=8989898;
int main(){
    int n,m,s,d;//编号0到n-1
    cin>>n>>m>>s>>d;
    //初始化
    for(int i=0;i
        for(int j=0;j
            if(i!=j){
                road[i][j]=inf;cost[i][j]=inf;
            }
            roadMin[i]=costMin[i]=inf;
        }
    }
    for(int i=0;i
        int a,b,len,c;
        cin>>a>>b>>len>>c;
        road[a][b]=road[b][a]=len;
        cost[a][b]=cost[b][a]=c;
    }
    //计算
    roadMin[s]=0,costMin[s]=0;
    for(int i=0;i
        int u=-1,temp=inf;
        for(int j=0;j
            if(roadMin[j]
                u=j;
                temp=roadMin[j];
            }
        }
        if(u==-1)break;
        vis[u]=1;
        //更新
        for(int v=0;v
            if(!vis[v]&&roadMin[u]+road[u][v]
                roadMin[v]=roadMin[u]+road[u][v];
                pre[v].clear();pre[v].push_back(u);
                costMin[v]=costMin[u]+cost[u][v];
            }
            else if(!vis[v]&&roadMin[u]+road[u][v]==roadMin[v]){
                if(costMin[u]+cost[u][v]
                    pre[v].clear();pre[v].push_back(u);
                    costMin[v]=costMin[u]+cost[u][v];
                }
            }
        }
    }
    //输出答案
    int t=d;
    vector<int>ans;
    ans.push_back(d);
    while(s!=d){
        d=pre[d][0];
        ans.push_back(d);
    }
    for(int i=ans.size()-1;i>=0;i--)cout<" ";
    cout<" "<
    return 0;
}