poj2502

最短路

#include <iostream>
#include <cstdlib>
#include <cstring>
#include <cstdio>
#include <cmath>
using namespace std;

#define maxn 205

struct Point
{
    double x, y;
}point[maxn];

double map[maxn][maxn];
double subv, walkv;
int n;

double dist(Point &a, Point &b)
{
    Point p;
    p.x = a.x - b.x;
    p.y = a.y - b.y;
    return sqrt(p.x * p.x + p.y * p.y);
}

void input()
{
    for (int i = 0; i < 2; i++)
        scanf("%lf%lf", &point[i].x, &point[i].y);
    n = 2;
    Point last, now;
    last.x = last.y = -1;
    while (~scanf("%lf%lf", &now.x, &now.y))
    {
        if (!(now.x == -1 && now.y == -1))
        {
            point[n++] = now;
            if (!(last.x == -1 && last.y == -1))
                map[n - 1][n - 2] = map[n - 2][n - 1] = dist(point[n - 1], point[n - 2]) / subv;
        }
        last = now;
    }
    for (int i = 0; i < n; i++)
        for (int j = 0; j < n; j++)
            if (map[i][j] == -1)
                map[i][j] = dist(point[i], point[j]) / walkv;
}

void floyd()
{
    for (int k = 0; k < n; k++)
        for (int i = 0; i < n; i++)
            for (int j = 0; j < n; j++)
                map[i][j] = min(map[i][j], map[i][k] + map[k][j]);
}

int main()
{
    //freopen("t.txt", "r", stdin);
    for (int i = 0; i < maxn; i++)
        for (int j = 0; j < maxn; j++)
            map[i][j] = -1;
    subv = 40 * 1000.0 / 60;
    walkv = 10 * 1000.0 / 60;
    input();
    floyd();
    printf("%.0f\n", map[0][1]);
    return 0;
}