oj.uz

Submission #523392

# Submission time Handle Problem Language Result Execution time Memory
523392 2022-02-07T15:12:39 Z wdjpng Paths (RMI21_paths) C++17
56 / 100
 423 ms 32532 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||false) 
        {
            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 0 ms 208 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 0 ms 208 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 296 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 0 ms 208 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 296 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 6 ms 556 KB Output is correct
9 Correct 6 ms 716 KB Output is correct
10 Correct 4 ms 588 KB Output is correct
11 Correct 5 ms 460 KB Output is correct
12 Correct 4 ms 460 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 0 ms 208 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 296 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 6 ms 556 KB Output is correct
9 Correct 6 ms 716 KB Output is correct
10 Correct 4 ms 588 KB Output is correct
11 Correct 5 ms 460 KB Output is correct
12 Correct 4 ms 460 KB Output is correct
13 Correct 37 ms 784 KB Output is correct
14 Correct 9 ms 1116 KB Output is correct
15 Correct 6 ms 920 KB Output is correct
16 Correct 61 ms 796 KB Output is correct
17 Correct 17 ms 844 KB Output is correct
18 Correct 10 ms 732 KB Output is correct
19 Correct 46 ms 716 KB Output is correct

Subtask #5
0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 380 ms 26904 KB Output is correct
2 Incorrect 423 ms 32532 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 0 ms 208 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 296 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 6 ms 556 KB Output is correct
9 Correct 6 ms 716 KB Output is correct
10 Correct 4 ms 588 KB Output is correct
11 Correct 5 ms 460 KB Output is correct
12 Correct 4 ms 460 KB Output is correct
13 Correct 37 ms 784 KB Output is correct
14 Correct 9 ms 1116 KB Output is correct
15 Correct 6 ms 920 KB Output is correct
16 Correct 61 ms 796 KB Output is correct
17 Correct 17 ms 844 KB Output is correct
18 Correct 10 ms 732 KB Output is correct
19 Correct 46 ms 716 KB Output is correct
20 Correct 380 ms 26904 KB Output is correct
21 Incorrect 423 ms 32532 KB Output isn't correct
22 Halted 0 ms 0 KB -