Frogger （Dijkstra）

#include <stdio.h>
#include <string.h>
#include <math.h>
#include <algorithm>
#define INF 0x3f3f3f3f
using namespace std;
double dist[201],grid[201][201];
int visit[201],n;
structnode
{
    double x,y;
}g[201];
double Dijkstra()
{
    double maxn,minc;
    int num=1,k,i;
    memset (visit,0,sizeof(visit));
    for (i = 1; i <= n; i++)
        dist[i] = grid[1][i];
    visit[1]=1;
    dist[1]=0;
    while(num++<n)   //当num小于图中的顶点的个数
    {
        minc=INF;
        for (i=1;i<=n;i++)
            if(!visit[i] && dist[i]<minc)
            {k=i;minc=dist[i];}
        visit[k]=1;
        for (i=1;i<=n;i++)
            {
                maxn=max(dist[k],grid[k][i]);
                dist[i]=min(maxn,dist[i]);
            }
    }
    return dist[2];    //dist[1]是0;
}
int main()
{
    int p=1,j,i;
    double x,y;
    while ( scanf("%d",&n)!=EOF && n)
    {
        memset(g,0,sizeof(g));
        memset(grid,0,sizeof(grid));
        for(i=1;i<=n;i++)
        {
            scanf("%lf%lf",&x,&y);
            g[i].x=x;
            g[i].y=y;
        }
        for (i=1;i<=n;i++)
            for(j=i+1;j<=n;j++)
                grid[i][j]=grid[j][i]=sqrt((g[i].x-g[j].x)*(g[i].x-g[j].x)+(g[i].y-g[j].y)*(g[i].y-g[j].y));
        printf("Scenario #%d\n",p++);
        printf("Frog Distance = %.3f\n\n",Dijkstra());
    }
	return 0;
}