Submission #626944

#	Time	Username	Problem	Language	Result	Execution time	Memory
626944		Glory	Paths (RMI21_paths)	C++17	0 / 100	151 ms	58368 KiB

Main

#include<bits/stdc++.h>
#define int long long
using namespace std;
int n,k,res=0,l[100005],d[100005];
int sparse_table[100005][25];
vector<pair<int,int>> gr[100005];
pair<int,int> a;
 
void dfs(int u,int par,int dh,int lh) {
    sparse_table[u][0] = par;
    l[u] = lh;
    d[u] = dh;
    for (auto [v,w]: gr[u]){
        if(v != par){
            dfs(v,u,w+dh,lh+1);
        }
    }
}
 
void dfs_1(int u,int par,int dh) {
    a = max(a, {dh,u});
    for(auto [v,w]: gr[u]){
        if(v != par){
            dfs_1(v, u, w+dh);
        }
    }
}

void preprocess_lca() {
    
 
    for (int k = 1; k <= 20; k++){
        for (int i = 1; i <= n; i++){
            sparse_table[i][k] = sparse_table[sparse_table[i][k - 1]][k - 1];
        }
    }
}
 
int lca(int p, int q) {
    
    for (int i = 20; i >= 0; i--){
        if (l[sparse_table[p][i]] >= l[q]){
            p = sparse_table[p][i];
        }
    }
    for (int i = 20; i >= 0; i--){
        if (l[sparse_table[q][i]] >= l[p]){
            q = sparse_table[q][i];
        }
    }
 
    if (p == q){
        return p;
    }
    
    for (int i = 20; i >= 0; i--){
        if (sparse_table[p][i] != sparse_table[q][i]) {
            p = sparse_table[p][i];
            q = sparse_table[q][i];
        }
    }
    return sparse_table[p][0];
}

int32_t main(){
    cin>>n>>k;
    for(int i = 1;i < n; i++){
        int u,v,w;
        cin>>u>>v>>w;
        gr[u].push_back({v,w});
        gr[v].push_back({u,w});
    }
    
    
    a = {-100,-100};
    dfs_1(1,-1,0);
    int pa = a.second;
    
    a = {-100,-100};
    dfs_1(pa,-1,0);
    int pb = a.second;
    
    
    dfs(1,-1,0,0);
    preprocess_lca();
    
    for(int i = 1;i <= n; i++){
       cout<<max(d[i]+d[pa]-d[lca(i,pa)]*2, d[i]+d[pb]-d[lca(i,pb)]*2)<<endl;
    }
}

• Subtask 1: 0 / 8
• Subtask 2: 0 / 11
• Subtask 3: 0 / 17
• Subtask 4: 0 / 20
• Subtask 5: 0 / 12
• Subtask 6: 0 / 32