【codevs1079】回家

problem

solution

codes

//标程Dijkstra
#include<iostream>
#include<algorithm>
#include<vector>
using namespace std;

//T
int n = 60, m, vis[1010];

//Graph
struct Edge{
    int v, w;
    Edge(int v, int w):v(v),w(w){}
};
vector<Edge>G[70];

//Dijkstra
int dis[70], book[70], s = (int)'Z'-'A';
void Dijkstra(){
    for(int i = 0; i < n; i++)dis[i] = 0xffffff;
    for(int i = 0; i < G[s].size(); i++)//bugs数据可能有覆盖
        dis[G[s][i].v] = min(dis[G[s][i].v],G[s][i].w);
    dis[s] = 0;  book[s] = 1;
    for(int i = 0; i < n; i++){
        int v, w=0xffffff;
        for(int j = 0; j < n; j++)
            if(!book[j] && dis[j]<w)
                w = dis[v=j];
        book[v] = 1;
        for(int j = 0; j < G[v].size(); j++)
            dis[G[v][j].v] = min(dis[G[v][j].v], w+G[v][j].w);
    }
}

int main(){
    cin>>m;
    for(int i = 1; i <= m; i++){
        char a, b; int w;  cin>>a>>b>>w;
        int x = a-'A', y = b-'A';
        if(x>=0 && x<25)vis[x] = 1;
        if(y>=0 && y<25)vis[y] = 1;
        G[x].push_back(Edge(y,w));
        G[y].push_back(Edge(x,w));
    }
    Dijkstra();
    int v, w=0xffffff;
    for(int i = 0; i < n; i++)
        if(vis[i] && dis[i]<w)
            w = dis[v=i];
    cout<<(char)(v+'A')<<" "<<w<<"
";
    return 0;
}

//数据太小, Floyd一番水
#include<iostream>
#include<algorithm>
using namespace std;
int n = 60, m;
int e[1010][1010], vis[1010];
int main(){
    cin>>m;
    for(int i = 0; i < n; i++)
        for(int j = 0; j < n; j++)
            e[i][j] = i==j ? 0 : 0xffffff;
    for(int i = 0; i < m; i++){
        char a, b; int w;  cin>>a>>b>>w;
        int x = a-'A', y = b-'A';
        if(x>=0 && x<25)vis[x] = 1;
        if(y>=0 && y<25)vis[y] = 1;
        //bugs数据可能有覆盖
        e[x][y] = min(e[x][y], w);
        e[y][x] = min(e[y][x], w);
    }
    for(int k = 0; k < n; k++)
        for(int i = 0; i < n; i++)
            for(int j = 0; j < n; j++)
                e[i][j] = min(e[i][j], e[i][k]+e[j][k]);
    int ans2 = 0xffffff, ans1;
    for(int i = 0; i < n; i++)if(vis[i] && e[i][(int)'Z'-'A']<ans2){
        ans2 = e[i][(int)'Z'-'A'];
        ans1 = i;
    }
    cout<<(char)(ans1+'A')<<" "<<ans2;
    return 0;
}