pku1502 Subway

http://poj.org/problem?id=2502

图论，最短路，dijkstra

交大模板

#include <stdio.h>
#include <string.h>
#include <math.h>
#define N 234

float dis[N], g[N][N];
int n, x[N], y[N];
bool v[N];
const float inf = 12345;

float min(float x, float y)
{
    return x<y? x: y;
}

void dijkstra()
{
    for(int i=1; i<=n; i++)
    {
        dis[i] = inf;
    }
    dis[1] = 0;
    memset(v, 0, sizeof(v));
    for(int i=1; i<=n; i++)
    {
        int mark = -1;
        float mindis = inf;
        for(int j=1; j<=n; j++)
        {
            if(!v[j] && dis[j] < mindis)
            {
                mindis = dis[j];
                mark = j;
            }
        }
        v[mark] = 1;
        for(int j=1; j<=n; j++)
        {
            dis[j] = min(dis[j], dis[mark] + g[mark][j]);
        }
    }
}

float d(int i, int j)
{
    return (float)sqrt( (double)(x[i]-x[j])*(x[i]-x[j]) + (double)(y[i]-y[j])*(y[i]-y[j]) );
}

int main()
{
    int i, j;
    float temp;
    for(i=0; i<N; i++)
    {
        for(j=0; j<N; j++)
        {
            g[i][j] = inf;
        }
    }
    scanf("%d%d%d%d", x+1, y+1, x+2, y+2);
    g[1][2] = g[2][1] = min(g[1][2], d(1, 2)*0.006);
    i = 3;
    while(~scanf("%d%d", x+i, y+i), x[i]+1)
    {
        for(j=0; j<i; j++)
        {
            g[i][j] = g[j][i] = min(g[i][j], d(i, j)*0.006);
        }
        for(i=i+1; scanf("%d%d", x+i, y+i), x[i]+1||y[i]+1; i++)
        {
            j = i - 1;
            g[i][j] = g[j][i] = min(g[i][j], d(i, j)*0.0015);
            for(j=0; j<i; j++)
            {
                g[i][j] = g[j][i] = min(g[i][j], d(i, j)*0.006);
            }
        }
    }
    n = i - 1;
    dijkstra();
    printf("%.0f\n", dis[2]);
    return 0;
}