Submission #523363

# Submission time Handle Problem Language Result Execution time Memory
523363 2022-02-07T14:36:50 Z wdjpng Paths (RMI21_paths) C++17
68 / 100
600 ms 32576 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;
void meta_dfs(int v, int p, topkmultiset&ts, vector<vector<edge>>& E)
{
    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 
        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;
            }
        }

        auto tmp = *best_it;
        auto mod = tmp;
        mod.first+=e.c;
        ts.replace(tmp, mod);

        sol[e.w]=ts.sum;
        meta_dfs(e.w,v,ts, E);

        // 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);
    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)
      |                              ~~~~~~~~~~~^~
# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
# 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 296 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
# 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 296 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 560 KB Output is correct
9 Correct 3 ms 588 KB Output is correct
10 Correct 4 ms 588 KB Output is correct
11 Correct 6 ms 504 KB Output is correct
12 Correct 4 ms 556 KB Output is correct
# 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 296 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 560 KB Output is correct
9 Correct 3 ms 588 KB Output is correct
10 Correct 4 ms 588 KB Output is correct
11 Correct 6 ms 504 KB Output is correct
12 Correct 4 ms 556 KB Output is correct
13 Correct 33 ms 708 KB Output is correct
14 Correct 9 ms 972 KB Output is correct
15 Correct 8 ms 844 KB Output is correct
16 Correct 30 ms 780 KB Output is correct
17 Correct 16 ms 808 KB Output is correct
18 Correct 9 ms 652 KB Output is correct
19 Correct 43 ms 716 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 370 ms 27356 KB Output is correct
2 Correct 354 ms 32576 KB Output is correct
3 Correct 311 ms 27296 KB Output is correct
4 Correct 345 ms 27300 KB Output is correct
5 Correct 381 ms 29240 KB Output is correct
6 Correct 353 ms 27320 KB Output is correct
# 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 296 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 560 KB Output is correct
9 Correct 3 ms 588 KB Output is correct
10 Correct 4 ms 588 KB Output is correct
11 Correct 6 ms 504 KB Output is correct
12 Correct 4 ms 556 KB Output is correct
13 Correct 33 ms 708 KB Output is correct
14 Correct 9 ms 972 KB Output is correct
15 Correct 8 ms 844 KB Output is correct
16 Correct 30 ms 780 KB Output is correct
17 Correct 16 ms 808 KB Output is correct
18 Correct 9 ms 652 KB Output is correct
19 Correct 43 ms 716 KB Output is correct
20 Correct 370 ms 27356 KB Output is correct
21 Correct 354 ms 32576 KB Output is correct
22 Correct 311 ms 27296 KB Output is correct
23 Correct 345 ms 27300 KB Output is correct
24 Correct 381 ms 29240 KB Output is correct
25 Correct 353 ms 27320 KB Output is correct
26 Execution timed out 1049 ms 26180 KB Time limit exceeded
27 Halted 0 ms 0 KB -