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
- Spring 内部方法调用失效问题(AOP)
AOP使用的是动态代理的机制,它会给类生成一个代理类,事务的相关操作都在代理类上完成.内部方式使用this调用方式时,使用的是实例调用,并没有通过代理类调用方法,所以会导致事务失效. 解决办法 方式一 ...
- Spring ( 三 ) Spring的Bean的装配与生命周期、专用测试
个人博客网:https://wushaopei.github.io/ (你想要这里多有) 一.对象的生命周期 1.IOC之Bean的生命周期 创建带有生命周期方法的bean public cla ...
- ASP.NET的Web网页如何进行分页操作(Demo举例)
大概说一下思路,可以利用sql的 Offset/Fetch Next分页,点击这里 这里的Demo利用LINQ的写好的方法 //这里是某个表的列表 skip是跳过前面的多少条数据 take这是跳过前面 ...
- Java实现 蓝桥杯VIP 算法训练 瓷砖铺放
[题目描述]: 有一长度为N(1< =N< =10)的地板,给定两种不同瓷砖:一种长度为1,另一种长度为2,数目不限.要将这个长度为N的地板铺满,一共有多少种不同的铺法? 例如,长度为4的 ...
- Java实现 蓝桥杯VIP 算法训练 大小写判断
问题描述 给定一个英文字母判断这个字母是大写还是小写. 输入格式 输入只包含一个英文字母c. 输出格式 如果c是大写字母,输出"upper",否则输出"lower&quo ...
- Pi-star MMDVM双工板介绍
Pi-star MMDVM双工板介绍(2020/2) pi-star里控制模式选择:双工模式(DUPLEX Mode)/单工模式(SIMPLE Mode) 双工板工作频率范围:144-148,219- ...
- Tidyverse| XX_join :多个数据表(文件)之间的各种连接
本文首发于公众号:“生信补给站” Tidyverse| XX_join :多个数据表(文件)之间的各种连接 前面分享了单个文件中的select列,filter行,列拆分等,实际中经常是多个数据表,综合 ...
- iOS - 多线程——GCD
什么是GCD Grand Central Dispatch(强大的调度器),是一个C语言API: 作用:多核并行运算的解决方案: GCD中有2个核心概念 ...
- C语言-耶稣门徒
<span style="font-family: Arial, Helvetica, sans-serif;"> </span> <span sty ...
- AS中将module转成library的步骤
转换步骤是在Android Studio 2.3版本下进行的,其他版本未测试 将要变成library的module的gradle文件的第一行 修改前:apply plugin: 'com.Androi ...