oj.uz

답안 #523410

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
523410 2022-02-07T15:31:11 Z wdjpng Paths (RMI21_paths) C++17
68 / 100
 600 ms 31700 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||v==1||E[v].size()!=2) 
        {
            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;
        if(bestedge.first!=-1&&v!=1&&E[v].size()==2) assert(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

# 결과 실행 시간 메모리 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

# 결과 실행 시간 메모리 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 292 KB Output is correct
7 Correct 1 ms 332 KB Output is correct

Subtask #3
17.0 / 17.0

# 결과 실행 시간 메모리 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 292 KB Output is correct
7 Correct 1 ms 332 KB Output is correct
8 Correct 5 ms 560 KB Output is correct
9 Correct 4 ms 700 KB Output is correct
10 Correct 3 ms 588 KB Output is correct
11 Correct 5 ms 460 KB Output is correct
12 Correct 4 ms 556 KB Output is correct

Subtask #4
20.0 / 20.0

# 결과 실행 시간 메모리 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 292 KB Output is correct
7 Correct 1 ms 332 KB Output is correct
8 Correct 5 ms 560 KB Output is correct
9 Correct 4 ms 700 KB Output is correct
10 Correct 3 ms 588 KB Output is correct
11 Correct 5 ms 460 KB Output is correct
12 Correct 4 ms 556 KB Output is correct
13 Correct 35 ms 804 KB Output is correct
14 Correct 9 ms 1116 KB Output is correct
15 Correct 6 ms 844 KB Output is correct
16 Correct 30 ms 776 KB Output is correct
17 Correct 16 ms 848 KB Output is correct
18 Correct 10 ms 728 KB Output is correct
19 Correct 42 ms 716 KB Output is correct

Subtask #5
12.0 / 12.0

# 결과 실행 시간 메모리 Grader output
1 Correct 366 ms 25348 KB Output is correct
2 Correct 349 ms 31700 KB Output is correct
3 Correct 306 ms 25784 KB Output is correct
4 Correct 369 ms 25712 KB Output is correct
5 Correct 373 ms 27924 KB Output is correct
6 Correct 357 ms 25628 KB Output is correct

Subtask #6
0 / 32.0

# 결과 실행 시간 메모리 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 292 KB Output is correct
7 Correct 1 ms 332 KB Output is correct
8 Correct 5 ms 560 KB Output is correct
9 Correct 4 ms 700 KB Output is correct
10 Correct 3 ms 588 KB Output is correct
11 Correct 5 ms 460 KB Output is correct
12 Correct 4 ms 556 KB Output is correct
13 Correct 35 ms 804 KB Output is correct
14 Correct 9 ms 1116 KB Output is correct
15 Correct 6 ms 844 KB Output is correct
16 Correct 30 ms 776 KB Output is correct
17 Correct 16 ms 848 KB Output is correct
18 Correct 10 ms 728 KB Output is correct
19 Correct 42 ms 716 KB Output is correct
20 Correct 366 ms 25348 KB Output is correct
21 Correct 349 ms 31700 KB Output is correct
22 Correct 306 ms 25784 KB Output is correct
23 Correct 369 ms 25712 KB Output is correct
24 Correct 373 ms 27924 KB Output is correct
25 Correct 357 ms 25628 KB Output is correct
26 Execution timed out 1090 ms 24616 KB Time limit exceeded
27 Halted 0 ms 0 KB -