【luogu P2984 [USACO10FEB]给巧克力Chocolate Giving】 题解
题目链接:https://www.luogu.org/problemnew/show/P2984
练习SPFA,把FJ当做起点,求出到所有牛的最短路,再把两个牛的相加。
#include <cstdio>
#include <queue>
#include <iostream>
#include <algorithm>
#include <cstring>
using namespace std;
const int maxn = ;
const int inf = 0x7fffffff;
int n, m, b, dis[maxn];
bool vis[maxn];
struct edge{
int len, to, next, from;
}e[maxn];
int head[maxn], cnt;
queue<int> q;
void add(int u, int v, int w)
{
e[++cnt].from = u;
e[cnt].to = v;
e[cnt].len = w;
e[cnt].next = head[u];
head[u] = cnt;
}
int SPFA()
{
while(!q.empty())
{
int now = q.front();
q.pop();
vis[now] = ;
for(int i = head[now]; i ; i = e[i].next)
{
if(dis[e[i].to] > dis[now] + e[i].len)
{
dis[e[i].to] = dis[now] + e[i].len;
if(!vis[e[i].to])
{
vis[e[i].to] = ;
q.push(e[i].to);
}
}
}
}
}
int main()
{
scanf("%d%d%d",&n,&m,&b);
for(int i = ; i <= m; i++)
{
int u,v,w;
scanf("%d%d%d",&u,&v,&w);
add(u,v,w);
add(v,u,w);
}
for(int i = ; i <= n; i++)
dis[i] = inf;
dis[] = ;
q.push();
vis[] = ;
SPFA();
for(int i = ; i <= b; i++)
{
int p,q;
scanf("%d%d",&p,&q);
printf("%d\n",dis[p]+dis[q]);
}
return ;
}
【luogu P2984 [USACO10FEB]给巧克力Chocolate Giving】 题解的更多相关文章
- 洛谷——P2984 [USACO10FEB]给巧克力Chocolate Giving
https://www.luogu.org/problem/show?pid=2984 题目描述 Farmer John is distributing chocolates at the barn ...
- 洛谷 P2984 [USACO10FEB]给巧克力Chocolate Giving
题目描述 Farmer John is distributing chocolates at the barn for Valentine's day, and B (1 <= B <= ...
- 洛谷 P2983 [USACO10FEB]购买巧克力Chocolate Buying 题解
P2983 [USACO10FEB]购买巧克力Chocolate Buying 题目描述 Bessie and the herd love chocolate so Farmer John is bu ...
- luogu P2985 [USACO10FEB]吃巧克力Chocolate Eating
题目描述 Bessie拿到了N (1 <= N <= 50,000)块巧克力.她决定想个办法吃掉这些巧克力,使得它在吃巧克力的这段时间里,最不开心的一天尽可能的开心.并且一共吃D (1 & ...
- [USACO10FEB]给巧克力Chocolate Giving
题意简叙: FarmerFarmerFarmer JohnJohnJohn有B头奶牛(1<=B<=25000)(1<=B<=25000)(1<=B<=25000), ...
- P2985 [USACO10FEB]吃巧克力Chocolate Eating
P2985 [USACO10FEB]吃巧克力Chocolate Eating 题目描述 Bessie has received N (1 <= N <= 50,000) chocolate ...
- 洛谷——P2983 [USACO10FEB]购买巧克力Chocolate Buying
P2983 [USACO10FEB]购买巧克力Chocolate Buying 题目描述 Bessie and the herd love chocolate so Farmer John is bu ...
- 洛谷 P2983 [USACO10FEB]购买巧克力Chocolate Buying
购买巧克力Chocolate Buying 乍一看以为是背包,然后交了一个感觉没错的背包上去. #include <iostream> #include <cstdio> #i ...
- 洛谷P2983 [USACO10FEB]购买巧克力Chocolate Buying
题目描述 Bessie and the herd love chocolate so Farmer John is buying them some. The Bovine Chocolate Sto ...
随机推荐
- Coursera 机器学习 第9章(下) Recommender Systems 学习笔记
9.5 Predicting Movie Ratings9.5.1 Problem Formulation推荐系统.推荐系统的问题表述:电影推荐.根据用户对已看过电影的打分来推测用户对其未打分的电影将 ...
- linux下Oracle 相关命令
#注意:例子中的oralce命令在/home/oracle/oracle/product/10.2.0/db_1/bin目录.#你可以自己修改成自己的目录. A.#dbstart //启动数据库 #d ...
- 将 flask 中的 session 存储到 SQLite 数据库中
将 flask 中的 session 存储到 SQLite 数据库中 使用 flask 构建服务器后端时,常需要在浏览器端存储 cookie 用于识别不同用户,根据不同的 cookie 判断出当前请求 ...
- 面试题 数据库sql
一.建表的结构和数据,在sqlserver直接用就行了 USE [test] GO /****** Object: Table [dbo].[TEACHER] Script Date: 05/16/2 ...
- 【Elasticsearch】集群管理
8.1 Elasticsearch时光机 Elasticsearch的快照,防止出错,灾备8.1.1 创建快照存储库创建快照之前必须建一个存储库,有如下几个方面,name,type,settings, ...
- 拼凑的宿主-host
开发两年之久,竟然不知道host这个词是什么意思.前些天有幸遇到了,就跟别人请教了.今天理絮一下.总比不知道强吧. 白话来说宿主就是一些框架运行机制运行时需要依赖的平台. 例如web开发常用的IIS, ...
- kafka自定义序列化器
<kafka权威指南> Customer.java public class Customer { private int customId; private String custome ...
- express 请求跨域后端解决方法CORS
CORS全称Cross-Origin Resource Sharing,是HTML5规范定义的如何跨域访问资源. Origin表示本域,也就是浏览器当前页面的域.当JavaScript向外域(如sin ...
- asp: AJAX Database
<% @LANGUAGE="VBSCRIPT" CODEPAGE="65001" %> <!DOCTYPE html PUBLIC " ...
- 【linux学习笔记】began,每次玩这个都特别着迷
胡乱的安装,通过虚拟机,从DVD加载开始,当然网上有大段的装机教程,装了两个Linux发行版,一个是centos7,一个是ubuntu18.04. 分区那些事: 因为处于学习阶段,所以总是因为分区问题 ...