Buy a Ticket 【最短路】
题目
Musicians of a popular band "Flayer" have announced that they are going to "make their exit" with a world tour. Of course, they will visit Berland as well.
There are n cities in Berland. People can travel between cities using two-directional train routes; there are exactly m routes, i-th route can be used to go from city v i to city u i (and from u i to v i), and it costs w i coins to use this route.
Each city will be visited by "Flayer", and the cost of the concert ticket in i-th city is a i coins.
You have friends in every city of Berland, and they, knowing about your programming skills, asked you to calculate the minimum possible number of coins they have to pay to visit the concert. For every city i you have to compute the minimum number of coins a person from city i has to spend to travel to some city j (or possibly stay in city i), attend a concert there, and return to city i (if j ≠ i).
Formally, for every you have to calculate , where d(i, j) is the minimum number of coins you have to spend to travel from city i to city j. If there is no way to reach city j from city i, then we consider d(i, j) to be infinitely large.
Input
The first line contains two integers n and m (2 ≤ n ≤ 2·105, 1 ≤ m ≤ 2·105).
Then m lines follow, i-th contains three integers v i, u i and w i (1 ≤ v i, u i ≤ n, v i ≠ u i, 1 ≤ w i ≤ 1012) denoting i-th train route. There are no multiple train routes connecting the same pair of cities, that is, for each (v, u) neither extra (v, u) nor (u, v) present in input.
The next line contains n integers a 1, a 2, ... a k (1 ≤ a i ≤ 1012) — price to attend the concert in i-th city.
Output
Print n integers. i-th of them must be equal to the minimum number of coins a person from city i has to spend to travel to some city j (or possibly stay in city i), attend a concert there, and return to city i (if j ≠ i).
Input 1
4 2
1 2 4
2 3 7 
6 20 1 25
Output 1
6 14 1 25
Input 2
3 3
1 2 1
2 3 1
1 3 1
30 10 20
Output 2
12 10 12
分析
题意:有n个城市,m条路(双向联通),在每个城市将会有一场精彩的演唱会,每个城市的票价不一样,每条路的路费不一样,你在每个城市都有一个朋友,他们都想看演唱会,求每个朋友的花费最小值(票价+来回路费)
做法:加一个super源点,把所有的点都跟这个点建一条边,权值就是路费的大小。然后就可以Dij求最短路。答案就是2倍的边权加路费。
代码
#include <cstdio>
#include <queue>
#include <cstring>
#define ll long long
using namespace std;
const ll maxn = 2e5+;
struct Edge{
int to,d,next;
}e[maxn<<];
ll tot,head[maxn];
void add(ll x, ll y, ll z) {
e[++tot].next=head[x];
head[x] = tot;
e[tot].to = y; e[tot].d = z;
}
priority_queue<pair<ll,ll> > q;
ll dis[maxn];
bool v[maxn];
void dij(ll x) {
memset(dis,0x3f,sizeof(dis));
dis[x] = ;
q.push(make_pair(,x));
while (!q.empty()){
ll u = q.top().second;
q.pop();
if (v[u]) continue;
v[u] = ;
for(ll i=head[u];i;i=e[i].next){
ll v = e[i].to;
if (dis[v] > dis[u] + e[i].d) {
dis[v] = dis[u] + e[i].d;
q.push(make_pair(-dis[v], v));
}
}
}
}
int n, m;
int main() {
scanf("%lld%lld", &n, &m);
for(ll i=;i<=m;i++) {
ll x, y, z;
scanf("%lld%lld%lld", &x, &y, &z);
add(x, y, *z), add(y, x, *z);
}
for(ll i=;i<=n;i++){
ll x;
scanf("%lld",&x);
add(, i, x);
}
dij();
for(ll i= ;i<=n;i++)
printf("%lld ", dis[i]);
return ;
}
Buy a Ticket 【最短路】的更多相关文章
- Codeforces 938D. Buy a Ticket (最短路+建图)
		
<题目链接> 题目大意: 有n座城市,每一个城市都有一个听演唱会的价格,这n座城市由m条无向边连接,每天变都有其对应的边权.现在要求出每个城市的人,看一场演唱会的最小价值(总共花费的价值= ...
 - Codeforces 938 D. Buy a Ticket (dijkstra 求多元最短路)
		
题目链接:Buy a Ticket 题意: 给出n个点m条边,每个点每条边都有各自的权值,对于每个点i,求一个任意j,使得2×d[i][j] + a[j]最小. 题解: 这题其实就是要我们求任意两点的 ...
 - Codeforces  938D Buy a Ticket (转化建图 + 最短路)
		
题目链接 Buy a Ticket 题意 给定一个无向图.对于每个$i$ $\in$ $[1, n]$, 求$min\left\{2d(i,j) + a_{j}\right\}$ 建立超级源点$ ...
 - Codeforces 938.D Buy a Ticket
		
D. Buy a Ticket time limit per test 2 seconds memory limit per test 256 megabytes input standard inp ...
 - CodeForces - 938D-Buy a Ticket+最短路
		
Buy a Ticket 题意:有n个点和m条路(都收费),n个点在开演唱会,门票不同,对于生活在n个点的小伙伴,要求计算出每个小伙伴为了看一场演唱会要花费的最小价格: 思路: 这道题我一开始觉得要对 ...
 - Buy A Ticket(图论)
		
Buy A Ticket 题目大意 每个点有一个点权,每个边有一个边权,求对于每个点u的\(min(2*d(u,v)+val[v])\)(v可以等于u) solution 想到了之前的虚点,方便统计终 ...
 - Buy the Ticket{HDU1133}
		
Buy the TicketTime Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)Total ...
 - 【HDU 1133】 Buy the Ticket (卡特兰数)
		
Buy the Ticket Problem Description The "Harry Potter and the Goblet of Fire" will be on sh ...
 - 【高精度练习+卡特兰数】【Uva1133】Buy the Ticket
		
Buy the Ticket Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others) T ...
 - Buy the Ticket(卡特兰数+递推高精度)
		
Buy the Ticket Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others) Tota ...
 
随机推荐
- Java实现 蓝桥杯VIP 算法提高 三角形面积
			
算法提高 三角形面积 时间限制:1.0s 内存限制:256.0MB 问题描述 由三角形的三边长,求其面积. 提示:由三角形的三边a,b,c求面积可以用如下的公式: s=(a+b+c)/2 输入格式 由 ...
 - Java实现LeetCode_0001_Two Sum
			
import java.util.Arrays; import java.util.Scanner; public class TwoSum_1 { public static void main(S ...
 - Java实现 LeetCode 140 单词拆分II
			
class Solution { public List<String> wordBreak(String s, List<String> wordDict) { List&l ...
 - java实现机器人行走
			
某少年宫引进了一批机器人小车.可以接受预先输入的指令,按指令行动.小车的基本动作很简单,只有3种:左转(记为L),右转(记为R),向前走若干厘米(直接记数字). 例如,我们可以对小车输入如下的指令: ...
 - 2.keras-构建基本网络实现非线性回归
			
构建基本网络实现非线性回归 1.加载显示数据集 import tensorflow as tf import numpy as np import keras from keras.layers im ...
 - go mod 与单元测试
			
目录 go mod 创建mod 默认模块名 指定模块名 引入其他模块 go 单元测试 创建源文件和测试文件 calc.go calc_test.go 运行测试用例 go mod 为解决go模块间的相互 ...
 - VSCode最佳设置
			
最近在学习Vue,用VSCode开发.经过摸索,VSCode最佳设置. { "eslint.enable": false, "workbench.colorTheme&q ...
 - c++ vector基本函数、排序、查找用法
			
vector用法目录: 1.基本用法 2.vector的删除操作 3.vector的sort排序 4.翻转vector中的所有元素 5.find()函数的用法 6.vector实战(这里写的是我在最开 ...
 - (六)TestNg中的软断言和硬断言
			
原文链接:https://cloud.tencent.com/developer/article/1479172 前言 在执行自动化测试脚本的时候,我们需要自动判断测试脚本执行完成后的实际结果是否与预 ...
 - Python中的字段分割
			
很多时候我们要完成分词的任务,这篇文章讲的非常非常好.生动形象,原文是https://www.cnblogs.com/douzi2/p/5579651.html,作者是宋桓公.