xtu 1267 Highway 湘潭邀请赛H

Highway In ICPCCamp there were n towns conveniently numbered with 1,2,…,n connected with (n−1) roads. The i-th road connecting towns ai and bi has length ci. It is guaranteed that any two cities reach each other using only roads. Bobo would like to build (n−1) highways so that any two towns reach each using only highways. Building a highway between towns x and y costs him δ(x,y) cents, where δ(x,y) is the length of the shortest path between towns x and y using roads. As Bobo is rich, he would like to find the most expensive way to build the (n−1) highways. Input The input contains zero or more test cases and is terminated by end-of-file. For each test case: The first line contains an integer n. The i-th of the following (n−1) lines contains three integers ai, bi and ci. 1≤n≤105 1≤ai,bi≤n 1≤ci≤108 The number of test cases does not exceed 10. Output For each test case, output an integer which denotes the result. Sample Input 5 1 2 2 1 3 1 2 4 2 3 5 1 5 1 2 2 1 4 1 3 4 1 4 5 2 Sample Output 19 15

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#include 
#include 
#include 
#include 
#include 
using namespace std;
 
#define ll __int64
const int N=100005;
 
struct p{
    ll to,val;
};
 
struct pp{
    ll u,dis;
    bool operator < (const pp&r) const{
        return dis>r.dis;
    }
};
vector
G[N];
int n,vis[N];
ll dis[N];
 
int dijkstra(int s)
{
    memset(vis,0,sizeof(vis));
    memset(dis,0x3f,sizeof(dis));
    priority_queueq;
    dis[s]=0;
    q.push(pp{s,0});
    int k=1;
    while(!q.empty())
    {
        pp now=q.top();
        q.pop();
        if(vis[now.u]) continue;
        vis[now.u]=1;
        for(int i=0;idis[now.u]+t.val)
            {
                dis[t.to]=dis[now.u]+t.val;
                if(dis[k]q;
    vis[s]=1;
    q.push(pp{s,0});
    while(!q.empty())
    {
        pp now=q.front();
        q.pop();
        dis[now.u]=max(now.dis,dis[now.u]);
        for(int i=0;i

Highway In ICPCCamp there were n towns conveniently numbered with 1,2,…,n connected with (n−1) roads. The i-th road connecting towns ai and bi has length ci. It is guaranteed that any two cities reach each other using only roads. Bobo would like to build (n−1) highways so that any two towns reach each using only highways. Building a highway between towns x and y costs him δ(x,y) cents, where δ(x,y) is the length of the shortest path between towns x and y using roads. As Bobo is rich, he would like to find the most expensive way to build the (n−1) highways. Input The input contains zero or more test cases and is terminated by end-of-file. For each test case: The first line contains an integer n. The i-th of the following (n−1) lines contains three integers ai, bi and ci. 1≤n≤105 1≤ai,bi≤n 1≤ci≤108 The number of test cases does not exceed 10. Output For each test case, output an integer which denotes the result. Sample Input 5 1 2 2 1 3 1 2 4 2 3 5 1 5 1 2 2 1 4 1 3 4 1 4 5 2 Sample Output 19 15