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Submission #469099

# Submission time Handle Problem Language Result Execution time Memory
469099 2021-08-30T17:40:09 Z wdjpng Chase (CEOI17_chase) C++17
40 / 100
 4000 ms 491784 KB 
#include <bits/stdc++.h>
    
#pragma GCC optimize ("O3")
#pragma GCC optimize ("unroll-loops")
    
#define int long long
#define rep(i,n) for(int i = 0; i < n; i++)
    
using namespace std;
    
int n,v;
vector<int>p;
vector<vector<int>>mem;
vector<vector<signed>>E;

signed takei[100001][101];
signed notakei[100001][101];
int takemaxx[100001][101];
int notakemaxx[100001][101];
int takealtmaxx[100001][101];
int notakealtmaxx[100001][101];


int dfs(int pos, int bc, int parent)
{
    if(parent!=-1&&mem[pos][bc]!=-1) return mem[pos][bc];
    if(bc==0) return 0;
    
        
    int sum = 0;
    for(int w : E[pos])
    {
        if(w==parent) continue;
        sum+=p[w];
    }

    int maxx = 0;
    takemaxx[pos][bc]=0;
    takei[pos][bc] = -1;
    notakemaxx[pos][bc]=0;
    notakei[pos][bc] = -1;

    int t, nt;
    for(int w : E[pos])
    {
        if(w==parent) continue;
        nt = dfs(w, bc, pos);
        t = dfs(w, bc-1, pos) + sum;

        if(nt>notakemaxx[pos][bc])
        {
            notakei[pos][bc] = w;
            notakemaxx[pos][bc] = nt;
        }

        if(t>takemaxx[pos][bc])
        {
            takei[pos][bc] = w;
            takemaxx[pos][bc] = t;
        }

        maxx=max(maxx, nt);
        maxx=max(maxx, t);
    }

    takealtmaxx[pos][bc]  = 0;
    notakealtmaxx[pos][bc]=0;

    for(int w : E[pos])
    {
        if(w==parent) continue;
        nt = dfs(w, bc, pos);
        t = dfs(w, bc-1, pos) + sum;
        if(takei[pos][bc]!=-1&&takei[pos][bc]!=w)
        {
            takealtmaxx[pos][bc]=max(takealtmaxx[pos][bc], t);
        }
        if(notakei[pos][bc]!=-1&&notakei[pos][bc]!=w)
        {
            notakealtmaxx[pos][bc]=max(notakealtmaxx[pos][bc], nt);
        }
    }

    return mem[pos][bc] = maxx;
}
    
int bruteforce()
{
    int maxx=0;
    rep(i, n) 
    {
        mem.assign(n+1, vector<int>(v+1, -1));
        maxx=max(maxx, dfs(i+1, v, -1));
    }
    return maxx;
}

int mx=0;
void meta_dfs(int pos, int parent)
{
    rep(i, v+1) mx = max(mx, dfs(pos, i, -1));
    for(int w : E[pos])
    {
        if(w==parent) continue;
        for(int i = 1; i<= v; i++)
        {
            mem[pos][i] = 0;
            if(takei[pos][i]!=w) mem[pos][i] = max(mem[pos][i], takemaxx[pos][i]-p[w]);
            else mem[pos][i] = max(mem[pos][i], takealtmaxx[pos][i]-p[w]);
            if(notakei[pos][i]!=w) mem[pos][i] = max(mem[pos][i], notakemaxx[pos][i]);
            else mem[pos][i] = max(mem[pos][i], notakealtmaxx[pos][i]);
        }
        meta_dfs(w,pos);
    }
}
//
//void dfs2(int pos, int par)
//{
//    int sum = 0;
//    for(int w : E[pos])
//    {
//        sum+=p[w];
//        if(w!=par) dfs2(w,pos);
//    }
//    totsum[pos]=sum;
//}

signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    cin>>n>>v;
    p.resize(n+1);
    rep(i, n) cin>>p[i+1];
    
    E.resize(n+1);
    
    rep(i,n-1)
    {
        signed a,b;
        cin>>a>>b;
        E[a].push_back(b);
        E[b].push_back(a);
    }
    //dfs2(1,-1);
    //int maxx = dfs(1, v, -1);
    //if(n<=1000) maxx = bruteforce();
    //cout<<maxx<<"\n";
    
    mem.assign(n+1, vector<int>(v+1, -1));
    

    meta_dfs(1, -1);
    cout<<mx<<"\n";
}

Subtask #1
20.0 / 20.0

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

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 332 KB Output is correct
2 Correct 0 ms 332 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 0 ms 332 KB Output is correct
5 Correct 0 ms 204 KB Output is correct
6 Correct 0 ms 332 KB Output is correct
7 Correct 13 ms 5272 KB Output is correct
8 Correct 3 ms 4428 KB Output is correct
9 Correct 3 ms 4428 KB Output is correct
10 Correct 14 ms 5196 KB Output is correct
11 Correct 7 ms 4640 KB Output is correct
12 Correct 4 ms 4428 KB Output is correct

Subtask #3
0 / 30.0

# Verdict Execution time Memory Grader output
1 Execution timed out 4062 ms 491784 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #4
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 332 KB Output is correct
2 Correct 0 ms 332 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 0 ms 332 KB Output is correct
5 Correct 0 ms 204 KB Output is correct
6 Correct 0 ms 332 KB Output is correct
7 Correct 13 ms 5272 KB Output is correct
8 Correct 3 ms 4428 KB Output is correct
9 Correct 3 ms 4428 KB Output is correct
10 Correct 14 ms 5196 KB Output is correct
11 Correct 7 ms 4640 KB Output is correct
12 Correct 4 ms 4428 KB Output is correct
13 Execution timed out 4062 ms 491784 KB Time limit exceeded
14 Halted 0 ms 0 KB -