【hdu 2112】 HDU Today （ 最短路 Dijkstra）（map）

http://acm.hdu.edu.cn/showproblem.php?pid=2112

这道题给了一个将字符串与int对应的思路，就是使用map

这道题答案对了，但是没有AC，我也不知道为什么。。

 #include <iostream>
 #include <cstdio>
 #include <string>
 #include <queue>
 #include <vector>
 #include <map>
 using namespace std;
 const int Ni = ;
 const int INF = <<;

 typedef pair<int,int> pa;

 int dis[Ni],n;//dis使用1~n的部分

 vector<pair<int,int> > eg[Ni];

 void Dijkstra(int s)
 {
           int i,j;
           cout<<n<<endl;
           for(i=;i<=n;i++)//要到n
                     dis[i] = INF;

           priority_queue<pa>q;  //优先级队列：小顶堆
           dis[s] = ;
           q.push(make_pair(s,dis[s]));
           while(!q.empty())
           {
                     pa x = q.top();
                     q.pop();
                     int w = x.first;
                     for(j = ;j<eg[w].size();j++)//遍历x的所有邻接点
                     {
                               pa y = eg[w][j];//y是x的邻接点
                               int u = y.first;
                               if(dis[u]>x.second+y.second)
                               {
                                         dis[u] = x.second+y.second;
                                         q.push(make_pair(u,dis[u]));
                               }
                     }
           }

 }

 int main()
 {
           int m,d;//关系个数
           string a,b;
           map<string,int> mp;
           while(cin>>n && n!=-)
           {
                     mp.clear();
                     for(int i = ;i<=n;i++)
                               eg[i].clear();//初始化
                     cin>>a>>b;
                     bool flag = false;
                     if(a==b)
                               flag = true;
                     mp[a] = ;
                     mp[b] = ;
                     int k = ;
                     int w,u;
                     int t = n;
                     while(t--)
                     {
                               cin>>a>>b>>d;
                               if(!mp[a])
                               {
                                         w = k;
                                         mp[a] = k++;
                               }
                               if(!mp[b])
                               {
                                         u = k;
                                         mp[b] = k++;
                               }
                               eg[mp[a]].push_back(make_pair(mp[b],d));
                               eg[mp[b]].push_back(make_pair(mp[a],d));
                     }
                     if(flag)
                     {
                               cout<<"0\n";
                               continue;
                     }
                     Dijkstra();
                     if(dis[]!=INF)
                               cout<<dis[]<<endl;
                     else
                               cout<<"-1\n";
           }

           return ;
 }

第二次写，依旧WA

 #include <cstdio>
 #include <iostream>
 #include <string>
 #include <queue>
 #include <vector>
 #include <map>
 using namespace std;

 #define MEM(a,v) memset (a,v,sizeof(a))
 // a for address, v for value

 #define max(x,y) ((x)>(y)?(x):(y))
 #define max(x,y) ((x)>(y)?(x):(y))

 #define debug printf("!\n")

 const int L = ;
 const int INF = <<;

 int n;

 struct node
 {
           int x,w;

           node(){}
           node(int a,int b)
           { x= a;w =b;}

           bool operator <(const node& a) const
           {
                     return w<a.w;
           }
 };

 vector<node> va[L];
 int dis[L];

 void Dijkstra(int s)
 {
           int i;
           for(i=;i<=n;i++)
                     dis[i] = INF;

           dis[s] = ;

           priority_queue<node> q;
           q.push(node(s,dis[s]));

           while(!q.empty())
           {
                     node t = q.top();
                     q.pop();

                     int x = t.x;

                     for(i = ;i<va[x].size();i++)
                     {
                               node y = va[x][i];
                               if(dis[y.x]>y.w+t.w)
                               {
                                         dis[y.x] = y.w+t.w;
                                         q.push(node(y.x,dis[y.x]));
                               }
                     }
           }
 }

 int main()
 {
           int i,j;

           bool flag;

           char begin[],end[];
           char c[],d[];

           map<string,int> mp;

           int w,k;

           while(scanf("%d",&n)!=EOF && n!=-)
           {

                     mp.clear();

                     for(i = ;i<=n;i++)
                               va[i].clear();

                     flag = false;

                     scanf("%s%s",begin,end);

                     if(strcmp(begin,end) == )
                               flag = true;

                     mp[begin] = ;
                     mp[end] = ;

                     k = ;

                     for(i = ;i<n;i++)
                     {
                               scanf("%s%s%d",c,d,&w);

                               if(!mp[c])
                                         mp[c] = k++;
                               if(!mp[d])
                                         mp[d] = k++;

                               va[mp[c]].push_back(node(mp[d],w));
                     }

                     if(flag)
                     {
                               printf("0\n");
                               continue;
                     }
                     Dijkstra();
                     if(dis[]!=INF)
                               printf("%d\n",dis[]);
                     else
                               printf("-1\n");
           }

           return ;
 }

UPDATE:

AC,780MS

#include <iostream>
#include <string>
#include <cstring>
#include <cstdlib>
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <stack>
#include <queue>
#include <cctype>
#include <vector>
#include <iterator>
#include <set>
#include <map>
#include <sstream>
using namespace std;

#define mem(a,b) memset(a,b,sizeof(a))
#define pf printf
#define sf scanf
#define spf sprintf
#define pb push_back
#define debug printf("!\n")
#define INF 10000
#define MAXN 5010
#define MAX(a,b) a>b?a:b
#define blank pf("\n")
#define LL long long
#define ALL(x) x.begin(),x.end()
#define INS(x) inserter(x,x.begin())
#define pqueue priority_queue

#define INF 0x3f3f3f3f

int n,k;
int g[][];//map
int vis[],d[];
char name[][],str1[],str2[];

int dijkstra(int v)
{
    int i,j,min,dir;
    for(i=;i<k;i++)
    {
        vis[i]=;
        d[i]=g[v][i];
    }

    vis[v] = ;
    d[v]=;

    for(i = ;i<k;i++)
    {
        min = INF;
        for(j=;j<k;j++)
        {
            if(!vis[j] && min>d[j])
            {
                min = d[j];
                dir = j;
            }
        }
        if(min==INF) break;
        vis[dir]=;
        for(j=;j<k;j++)
        {
            if(!vis[j] && d[j] > d[dir]+g[dir][j])
                d[j] = d[dir]+g[dir][j];
        }
    }
    return d[];
}

int main()
{
    int a,num1,num2,i,j;
    while(sf("%d",&n)== && n!=-)
    {
        mem(g,);
        sf("%s %s",name[],name[]);
        k=;
        for(i = ;i<n;i++)
        {
            sf("%s %s %d",str1,str2,&a);
            for(j = ;j<k;j++)
            {
                if(strcmp(str1,name[j])==)
                {
                    num1 = j;
                    break;
                }
            }
            if(j==k)
            {
                num1 = k;
                strcpy(name[k++],str1);
            }
            for(j = ;j<k;j++)
            {
                if(strcmp(str2,name[j])==)
                {
                    num2 = j;
                    break;
                }
            }
            if(j==k)
            {
                num2 = k;
                strcpy(name[k++],str2);
            }
            if(g[num1][num2]>a)
                g[num1][num2]=a;
            if(g[num2][num1]>a)
                g[num2][num1]=a;

        }
        if(strcmp(name[],name[])==)
            pf("0\n");
        else
        {
            i = dijkstra();
            if(i>=INF)
                pf("-1\n");
            else
                pf("%d\n",i);
        }
    }
}