hdu 2066 一个人的旅行(最短路径 Dijkstra算法)

来源：互联网发布：软件程序编辑：程序博客网时间：2024/05/16 05:48

思路：Dijkstra求最短路径，将0节点作为原点，求出到各个点的距离。

#include <stdio.h>#include <string.h>#include <algorithm>using namespace std;#define inf 0x3fffffff#define N 1005int T,S,D,n,map[N][N],vis[N],cast[N],s[N],e[N];void Dijkstra(){    int i,j,minn,pos;    memset(vis,0,sizeof(vis));    vis[0] = 1;    for(i = 0; i<=n; i++)        cast[i] = map[0][i];    for(i = 1; i<=n; i++)    {        minn = inf;        for(j = 1; j<=n; j++)        {            if(cast[j]<minn && !vis[j])            {                pos = j;                minn = cast[j];            }        }        vis[pos] = 1;        for(j = 1; j<=n; j++)        {            if(cast[pos]+map[pos][j]<cast[j] && !vis[j])                cast[j] = cast[pos]+map[pos][j];        }    }}int main(){    int x,y,z;    while(~scanf("%d%d%d",&T,&S,&D))    {        n = 0;        for(int i = 0; i<N; i++)        {            for(int j = 0; j<N; j++)                map[i][j] = inf;            map[i][i] = 0;        }        while(T--)        {            scanf("%d%d%d",&x,&y,&z);            n = max(max(n,x),y);//n标记节点个数            if(z<map[x][y])                map[x][y] = map[y][x] = z;        }        for(int i = 0; i<S; i++)        {            scanf("%d",&s[i]);            map[0][s[i]] = map[s[i]][0] = 0;        }        for(int i = 0; i<D; i++)            scanf("%d",&e[i]);        Dijkstra();        int minn = inf;        for(int i = 0; i<D; i++)            minn = min(minn,cast[e[i]]);        printf("%d\n",minn);    }    return 0;}

0 0