oj.uz

Submission #523390

# Submission time Handle Problem Language Result Execution time Memory
523390 2022-02-07T15:10:52 Z wdjpng Paths (RMI21_paths) C++17
56 / 100
 455 ms 33348 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(find(all(topk), 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) 
        {
            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 1 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct

Subtask #2
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 1 ms 292 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 1 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 1 ms 292 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 5 ms 540 KB Output is correct
9 Correct 4 ms 656 KB Output is correct
10 Correct 4 ms 500 KB Output is correct
11 Correct 5 ms 548 KB Output is correct
12 Correct 5 ms 560 KB Output is correct

Subtask #4
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 1 ms 292 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 5 ms 540 KB Output is correct
9 Correct 4 ms 656 KB Output is correct
10 Correct 4 ms 500 KB Output is correct
11 Correct 5 ms 548 KB Output is correct
12 Correct 5 ms 560 KB Output is correct
13 Correct 42 ms 808 KB Output is correct
14 Correct 10 ms 1100 KB Output is correct
15 Correct 8 ms 944 KB Output is correct
16 Correct 35 ms 784 KB Output is correct
17 Correct 21 ms 812 KB Output is correct
18 Correct 9 ms 716 KB Output is correct
19 Correct 47 ms 708 KB Output is correct

Subtask #5
0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 455 ms 25248 KB Output is correct
2 Incorrect 399 ms 33348 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #6
0 / 32.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 1 ms 292 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 5 ms 540 KB Output is correct
9 Correct 4 ms 656 KB Output is correct
10 Correct 4 ms 500 KB Output is correct
11 Correct 5 ms 548 KB Output is correct
12 Correct 5 ms 560 KB Output is correct
13 Correct 42 ms 808 KB Output is correct
14 Correct 10 ms 1100 KB Output is correct
15 Correct 8 ms 944 KB Output is correct
16 Correct 35 ms 784 KB Output is correct
17 Correct 21 ms 812 KB Output is correct
18 Correct 9 ms 716 KB Output is correct
19 Correct 47 ms 708 KB Output is correct
20 Correct 455 ms 25248 KB Output is correct
21 Incorrect 399 ms 33348 KB Output isn't correct
22 Halted 0 ms 0 KB -