L3-007. 天梯地图

L3-007. 天梯地图

题目链接：https://www.patest.cn/contests/gplt/L3-007

Dijstra

这题是Dijstra的变形，麻烦的是两种最短路的相同距离时的选择条件不同，也就是说要写两个Dijstra函数。很早就写完了代码，不过debug了一星期，最后还是参考他人博客才知道自己错哪了= =(易错点已注释)

代码如下：

 #include<cstdio>
 #include<cstring>
 #include<stack>
 #define N 505
 using namespace std;
 const int INF=0x3f3f3f3f;
 bool mark[N];
 int n,Start,End;
 int lenmp[N][N];
 int timemp[N][N];
 int lendis[N];
 int timedis[N];
 int lenpre[N];
 int timepre[N];
 void lenDijstra();
 void timeDijstra();
 int main(void){
     /**输入**/
     memset(lenpre,-,sizeof(lenpre));
     memset(timepre,-,sizeof(timepre));
     int m;
     scanf("%d%d",&n,&m);
     for(int i=;i<n;++i){
         lendis[i]=INF;
         timedis[i]=INF;
         for(int j=;j<n;++j){
             lenmp[i][j]=INF;
             timemp[i][j]=INF;
         }
     }
     while(m--){
         int a,b,one,length,time;
         scanf("%d%d%d%d%d",&a,&b,&one,&length,&time);
         if(one){
             lenmp[a][b]=length;
             timemp[a][b]=time;
         }else{
             lenmp[a][b]=lenmp[b][a]=length;
             timemp[a][b]=timemp[b][a]=time;
         }
     }
     scanf("%d%d",&Start,&End);
     /**数据处理**/
     lenDijstra();
     timeDijstra();
     /**输出**/
     int k=End;
     bool flag=;
     stack<int>times;
     while(k!=Start){
         times.push(k);
         if(timepre[k]!=lenpre[k])flag=;
         k=timepre[k];
     }
     if(flag){
         printf("Time = %d;",timedis[End]);
         printf(" Distance = %d:",lendis[End]);
         printf("% d",Start);
         while(!times.empty()){
             printf(" => %d",times.top());
             times.pop();
         }
         printf("\n");
     }else{
         printf("Time = %d:",timedis[End]);
         printf("% d",Start);
         while(!times.empty()){
             printf(" => %d",times.top());
             times.pop();
         }
         printf("\n");
         printf("Distance = %d:",lendis[End]);
         printf("% d",Start);
         stack<int>diss;
         k=End;
         while(k!=Start){
             diss.push(k);
             k=lenpre[k];
         }
         while(!diss.empty()){
             printf(" => %d",diss.top());
             diss.pop();
         }
         printf("\n");
     }
     return ;
 }
 void lenDijstra(){
     int node[N];
     memset(node,,sizeof(node));
     node[Start]=;

     memset(mark,,sizeof(mark));
     lendis[Start]=;
     while(){
         int Min=INF,index;
         for(int i=;i<n;++i){
             if(mark[i]&&Min>lendis[i]){
                 Min=lendis[i];
                 index=i;
             }
         }
         if(Min==INF)break;
         mark[index]=;
         for(int i=;i<n;++i){
             int d=lendis[index]+lenmp[index][i];
             if(mark[i]&&lendis[i]>d){
                 lendis[i]=d;
                 lenpre[i]=index;
                 node[i]=node[index]+;                /*非node[i]++*/
             }else if(mark[i]&&lendis[i]==d&&node[index]+<node[i]){
                 lenpre[i]=index;
                 node[i]=node[index]+;
             }
         }
     }
 }
 void timeDijstra(){
     memset(mark,,sizeof(mark));
     int dis[N];
     for(int i=;i<n;++i)
         dis[i]=lenmp[Start][i];
     timedis[Start]=;
     dis[Start]=;
     while(){
         int Min=INF,index;
         for(int i=;i<n;++i){
             if(mark[i]&&Min>timedis[i]){
                 Min=timedis[i];
                 index=i;
             }
         }
         if(Min==INF)break;
         mark[index]=;
         for(int i=;i<n;++i){
             int t=timedis[index]+timemp[index][i];
             int d=dis[index]+lenmp[index][i];
             if(mark[i]&&timedis[i]>t){
                 dis[i]=d;
                 timedis[i]=t;
                 timepre[i]=index;
             }else if(mark[i]&&timedis[i]==t&&dis[i]>d){
                 dis[i]=d;
                 timepre[i]=index;
             }
         }
     }
 }