oj.uz

Submission #524120

# Submission time Handle Problem Language Result Execution time Memory
524120 2022-02-08T16:36:51 Z wdjpng Paths (RMI21_paths) C++17
100 / 100
 456 ms 34276 KB 
#ifndef LOCAL
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#endif
    
#include <bits/stdc++.h>
    
#define int long long
#define rep(i,n) for(int i =0; i<n;i++)
#define all(a) a.begin(), a.end()
    
using namespace std;
    
int k;
struct edge{
    int c, w;
};
    
struct topkmultiset{
    int k;
    int sum = 0;
    multiset<pair<int, int>>other,topk;
    void rebalance()
    {
        while (other.size()&&topk.size()<k)
        {
            auto a = other.rbegin();
            auto end  = *a;
            sum+=end.first;
            topk.insert(end);
            other.erase(end);
        }
        
        while (other.size()&&topk.size()&&*(other.rbegin())>*(topk.begin()))
        {
            auto a = *(other.rbegin()), b = *(topk.begin());
            sum+=a.first-b.first;
            topk.erase(b);
            other.insert(b);
            
            other.erase(a);
            topk.insert(a);
        }
        
    }
    
    void replace(pair<int, int> a, pair<int, int> b) {
        if(topk.find(a)!=topk.end()) {
            sum-=a.first;
            topk.erase(a);
        } else other.erase(a);
    
        other.insert(b);
        rebalance();
    }
};
    
int precount=0;
vector<int>pre,post;
void predfs(int v, int p, vector<vector<edge>>&E)
{
    pre[v]=precount++;
    for(auto e : E[v]) if(e.w!=p) predfs(e.w,v,E);
    post[v]=precount++;
}
    
vector<pair<int, int>>bestofsubtree;
multiset<pair<int, int>> dfs(int v, int p, vector<vector<edge>>& E)
{
    multiset<pair<int, int>> cs;
    cs.insert({0,v});
    
    for(edge e : E[v])
    {
        if(e.w==p) continue;
        multiset<pair<int, int>> ns = dfs(e.w, v, E);
    
        auto it = ns.end();
        it--;
        pair<int,int> tmp = *it;
        ns.erase(it);
        tmp.first+=e.c;
        ns.insert(tmp);
        bestofsubtree[e.w]=tmp;
    
        if(cs.size()<ns.size()) swap(cs, ns);
        for(auto x : ns) cs.insert(x);
    }
    
    // while (cs.size()>k+3) cs.erase(cs.begin()); 
    
    return cs;
}
    
    
vector<int>sol;
pair<int, int>defau = {-1,-1};
void meta_dfs(int v, int p, topkmultiset&ts, vector<vector<edge>>& E, pair<int, int>bestedge)
{
    for(edge e : E[v])
    {
        if(e.w==p) continue;
    
        // remove edge from child to root from biggest path of child
        pair<int, int>uchild = bestofsubtree[e.w];
        uchild.first-=e.c;
        ts.replace(bestofsubtree[e.w], uchild);
        
        // add that edge to biggest path not coming from subtree of child 
    
        pair<int, int>tmp;
        if(bestedge.first==-1||true) 
        {
            auto best_it = (ts.topk.rbegin());
            while (pre[(*best_it).second]>=pre[e.w]&&post[(*best_it).second]<=post[e.w]) {
                ++best_it;
                if(best_it==ts.topk.rend())
                {
                    best_it = ts.other.rbegin();
                    while (pre[(*best_it).second]>=pre[e.w]&&post[(*best_it).second]<=post[e.w])
                        ++best_it;
                    break;
                }
            }
            tmp=*best_it;
        } else tmp=bestedge;
        
        auto mod = tmp;
        mod.first+=e.c;
        ts.replace(tmp, mod);
        
        sol[e.w]=ts.sum;
        if(v!=1&&E[v].size()==2) meta_dfs(e.w,v,ts, E, mod);
        else meta_dfs(e.w,v,ts, E, defau);
        // remove child weight from biggest link
        ts.replace(mod, tmp);
    
        // place biggest link to child in again
        ts.replace(uchild, bestofsubtree[e.w]);
    }
}
    
    
signed main()
{
    int n;
    cin>>n>>k;
    
    bestofsubtree.assign(n+1, {-1,-1});
    pre.assign(n+1, -1);
    post.assign(n+1,-1);
    
    vector<vector<edge>>E(n+1);
    rep(i, n-1)
    {
        int a, b, c;
        cin>>a>>b>>c;
    
        E[a].push_back({c,b});
        E[b].push_back({c,a});
    }
    predfs(1,-1,E);
    sol.resize(n+1);
    multiset<pair<int, int>>s  = dfs(1, -1, E);
    topkmultiset ts = topkmultiset();
    ts.k=k;
    ts.other = s;
    ts.rebalance();
    sol[1]=ts.sum;
    
    meta_dfs(1, -1, ts, E, defau);
    for(int i = 1;i <= n; i++) cout<<sol[i]<<"\n";
}

Compilation message

Main.cpp: In member function 'void topkmultiset::rebalance()':
Main.cpp:25:41: warning: comparison of integer expressions of different signedness: 'std::multiset<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} and 'long long int' [-Wsign-compare]
   25 |         while (other.size()&&topk.size()<k)
      |                              ~~~~~~~~~~~^~

Subtask #1
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct

Subtask #2
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 332 KB Output is correct
5 Correct 1 ms 332 KB Output is correct
6 Correct 1 ms 332 KB Output is correct
7 Correct 1 ms 332 KB Output is correct

Subtask #3
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 332 KB Output is correct
5 Correct 1 ms 332 KB Output is correct
6 Correct 1 ms 332 KB Output is correct
7 Correct 1 ms 332 KB Output is correct
8 Correct 3 ms 544 KB Output is correct
9 Correct 3 ms 588 KB Output is correct
10 Correct 3 ms 460 KB Output is correct
11 Correct 3 ms 460 KB Output is correct
12 Correct 3 ms 460 KB Output is correct

Subtask #4
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 332 KB Output is correct
5 Correct 1 ms 332 KB Output is correct
6 Correct 1 ms 332 KB Output is correct
7 Correct 1 ms 332 KB Output is correct
8 Correct 3 ms 544 KB Output is correct
9 Correct 3 ms 588 KB Output is correct
10 Correct 3 ms 460 KB Output is correct
11 Correct 3 ms 460 KB Output is correct
12 Correct 3 ms 460 KB Output is correct
13 Correct 6 ms 716 KB Output is correct
14 Correct 5 ms 972 KB Output is correct
15 Correct 8 ms 844 KB Output is correct
16 Correct 6 ms 760 KB Output is correct
17 Correct 5 ms 716 KB Output is correct
18 Correct 4 ms 716 KB Output is correct
19 Correct 6 ms 716 KB Output is correct

Subtask #5
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 376 ms 25372 KB Output is correct
2 Correct 379 ms 30944 KB Output is correct
3 Correct 321 ms 25288 KB Output is correct
4 Correct 369 ms 25148 KB Output is correct
5 Correct 373 ms 27292 KB Output is correct
6 Correct 355 ms 25044 KB Output is correct

Subtask #6
32.0 / 32.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 332 KB Output is correct
5 Correct 1 ms 332 KB Output is correct
6 Correct 1 ms 332 KB Output is correct
7 Correct 1 ms 332 KB Output is correct
8 Correct 3 ms 544 KB Output is correct
9 Correct 3 ms 588 KB Output is correct
10 Correct 3 ms 460 KB Output is correct
11 Correct 3 ms 460 KB Output is correct
12 Correct 3 ms 460 KB Output is correct
13 Correct 6 ms 716 KB Output is correct
14 Correct 5 ms 972 KB Output is correct
15 Correct 8 ms 844 KB Output is correct
16 Correct 6 ms 760 KB Output is correct
17 Correct 5 ms 716 KB Output is correct
18 Correct 4 ms 716 KB Output is correct
19 Correct 6 ms 716 KB Output is correct
20 Correct 376 ms 25372 KB Output is correct
21 Correct 379 ms 30944 KB Output is correct
22 Correct 321 ms 25288 KB Output is correct
23 Correct 369 ms 25148 KB Output is correct
24 Correct 373 ms 27292 KB Output is correct
25 Correct 355 ms 25044 KB Output is correct
26 Correct 437 ms 25636 KB Output is correct
27 Correct 357 ms 30860 KB Output is correct
28 Correct 390 ms 32304 KB Output is correct
29 Correct 332 ms 25448 KB Output is correct
30 Correct 414 ms 25504 KB Output is correct
31 Correct 397 ms 25412 KB Output is correct
32 Correct 456 ms 28032 KB Output is correct
33 Correct 408 ms 25632 KB Output is correct
34 Correct 291 ms 25536 KB Output is correct
35 Correct 397 ms 25576 KB Output is correct
36 Correct 365 ms 34276 KB Output is correct