poj 2502 Subway md自闭了，之后再看吧f**k

Floyed

https://blog.youkuaiyun.com/u013480600/article/details/37875601

自己写的Floyed这个WA了，暂时还不知道为什么

//Floyed写法
#pragma warning(disable:4996)
#include<iostream>
#include<string>
#include<cmath>
#include<ctype.h>
#include<memory.h>
#include<string.h>
#include<algorithm>
#include<map>
#include<iomanip>
#include<set>
#include<list>
#include<vector>
#include<stack>
#include<queue>
#define ll long long int
using namespace std;
const int maxn = 210;
#define man_v (10000.0 / 60.0)
#define car_v (40000.0 / 60.0)

struct node
{
	double x, y;
};
node a[maxn];//用来保存数据

double Map[maxn][maxn];

double pow2(double x)
{
	return x * x;
}
double cal_time(int i, int j, double v)//坐标（i，j），速度为v
{
	//return sqrt(pow2(a[i].x - a[j].x) + pow2(a[i].y - a[j].y)) / v;

	return sqrt((a[i].x - a[j].x) * (a[i].x - a[j].x) + (a[i].y - a[j].y) * (a[i].y - a[j].y)) / v;

}

int main()
{
	for (int i = 0; i < maxn; i++)
		for (int j = 0; j < maxn; j++)
			Map[i][j] = i == j ? 0 : -1;

	cin >> a[0].x >> a[0].y >> a[1].x >> a[1].y;

	int cnt = 2;//a[maxn]已经保存了1和2，1 是起点家里，2是终点学校，所以从3开始记录

	//计算地铁的时间
	double pre_x = -1;//记录上一个坐标的x，防止计算时间的时候遇到已经到达终点的情况，那种情况直接不需要计算时间
	while (/*cin >> a[cnt].x >> a[cnt].y*/scanf("%lf%lf", &a[cnt].x, &a[cnt].y) == 2)
	{
		//每条地铁线路的终点后面是虚拟坐标对（-1，-1）
		if (pre_x != -1 && a[cnt].x != -1)//没有到达地铁终点，并且此次输入的也不是终点-1
		{
			//从上一站cnt-1站 到 这一站cnt站的时间,往返时间相同
			Map[cnt - 1][cnt] = Map[cnt][cnt - 1] = cal_time(cnt - 1, cnt, car_v);
		}
		pre_x = a[cnt].x;
		if (a[cnt].x != -1)
			cnt++;
	}

	//计算步行的时间
	for (int i = 0; i < cnt; i++)
		for (int j = i + 1; j < cnt; j++)
			//if (i != j)
			if (Map[i][j] == -1)
				Map[i][j] = Map[j][i] = cal_time(i, j, man_v);

	for (int k = 0; k < cnt; k++)
		for (int i = 0; i < cnt; i++)
			for (int j = 0; j < cnt; j++)
				if (Map[i][k] != -1 && Map[k][j] != -1)
					Map[i][j] = min(Map[i][j], Map[i][k] + Map[k][j]);
	cout << Map[0][1] << endl;//Map[1][2]表示从家到学校的最短距离/时间

	return 0;
}

Dijkstra

https://blog.youkuaiyun.com/llzhh/article/details/52421527

//Dijkstra写法
#pragma warning(disable:4996)
#include<iostream>
#include<string>
#include<cmath>
#include<ctype.h>
#include<memory.h>
#include<string.h>
#include<algorithm>
#include<map>
#include<iomanip>
#include<set>
#include<list>
#include<vector>
#include<stack>
#include<queue>
#define ll long long int
using namespace std;
const int INF = 0x3f3f3f3f;
const int maxn = 500;

double Map[maxn][maxn];
double dis[maxn];
int vis[maxn];
int n = 0;

double get_time(double x1, double y1, double x2, double y2)
{
	return sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2));
}
void dijkstra(int s)
{
	for (int i = 0; i < n; i++)
		dis[i] = Map[i][s];
	vis[s] = 1;
	for (int i = 0; i < n; i++)
	{
		int Min = INF;
		int min_index = -1;
		for (int j = 0; j < n; j++)
		{
			if (Min > dis[j] && !vis[j])
			{
				min_index = j;
				Min = dis[j];
			}
		}

		if (min_index != -1)
			vis[min_index] = 1;
		for (int j = 0; j < n; j++)
		{
			if (dis[j] > dis[min_index] + Map[min_index][j] && !vis[j])
				dis[j] = dis[min_index] + Map[min_index][j];
		}
	}
}

struct node
{
	int x, y;
};
node a[maxn];

int main()
{
	cin >> a[0].x >> a[0].y >> a[1].x >> a[1].y;
	n = 2;

	int pre = 2;
	double x, y;

	while (scanf("%lf %lf", &x, &y) != EOF)
	{
		if (x == -1 && y == -1)
		{
			for (int i = pre; i < n - 1; i++)
			{
				double len = get_time(a[i].x, a[i].y, a[i + 1].x, a[i + 1].y) / 40000.0;
				Map[i][i + 1] = Map[i + 1][i] = len;
			}
			pre = n;
			continue;
		}
		a[n].x = x;
		a[n].y = y;
		n++;
	}

	for (int i = 0; i < n; i++)
	{
		for (int j = i + 1; j < n; j++)
		{
			if (Map[i][j] == 0)
			{
				double len = get_time(a[i].x, a[i].y, a[j].x, a[j].y) / 10000.0;
				Map[i][j] = Map[j][i] = len;
			}
		}
	}

	dijkstra(0);
	printf("%d", (int)(dis[1] * 60.0 + 0.5));

	return 0;
}