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Submission #163121

# Submission time Handle Problem Language Result Execution time Memory
163121 2019-11-11T13:04:35 Z arnold518 Chase (CEOI17_chase) C++14
40 / 100
 4000 ms 98168 KB 
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int MAXN = 1e5;
const int MAXK = 100;

int N, K;
ll P[MAXN+10], S[MAXN+10], dp1[MAXN+10][MAXK+10], dp2[MAXN+10][MAXK+10], ans;
vector<int> adj[MAXN+10];

void dfs1(int now, int bef)
{
    int i, j;
    S[now]+=P[bef];
    for(int nxt : adj[now])
    {
        if(nxt==bef) continue;
        dfs1(nxt, now);
        S[now]+=P[nxt];
    }

    for(i=1; i<=K; i++)
    {
        ll val=0;
        for(int nxt : adj[now])
        {
            if(nxt==bef) continue;
            val=max(val, dp1[nxt][i-1]);
            dp1[now][i]=max(dp1[now][i], dp1[nxt][i]);
        }
        dp1[now][i]=max(dp1[now][i], S[now]-P[bef]+val);
    }
}

vector<pll> V[MAXK+10];
void dfs2(int now, int bef)
{
    int i, j;

    for(i=0; i<=K; i++) V[i].clear();
    for(int nxt : adj[now])
    {
        if(nxt==bef) continue;
        for(i=0; i<=K; i++) V[i].push_back({dp1[nxt][i], nxt});
    }
    for(i=0; i<=K; i++) V[i].push_back({dp2[bef][i], bef});
    for(i=0; i<=K; i++) sort(V[i].begin(), V[i].end(), greater<pll>());

    for(int nxt : adj[now])
    {
        if(nxt==bef) continue;
        for(i=1; i<=K; i++)
        {
            for(j=0; j<V[i].size(); j++)
            {
                if(V[i][j].second==nxt) continue;
                dp2[nxt][i]=max(dp2[nxt][i], V[i][j].first);
                break;
            }
            for(j=0; j<V[i-1].size(); j++)
            {
                if(V[i-1][j].second==nxt) continue;
                dp2[nxt][i]=max(dp2[nxt][i], V[i-1][j].first+S[now]-P[nxt]);
                break;
            }
        }
    }

    for(int nxt : adj[now])
    {
        if(nxt==bef) continue;
        dfs2(nxt, now);
    }
}

void dfs3(int now, int bef)
{
    for(int nxt : adj[now])
    {
        if(nxt==bef) continue;
        dfs3(nxt, now);
    }

    ll val1=0, val2=0;
    for(int nxt : adj[now])
    {
        if(nxt==bef) continue;
        val1=max(val1, dp1[nxt][K]);
    }
    val1=max(val1, dp2[now][K]);

    for(int nxt : adj[now])
    {
        if(nxt==bef) continue;
        val2=max(val2, dp1[nxt][K-1]);
    }
    val2=max(val2, dp2[now][K-1]);
    val2+=S[now];

    ans=max({ans, val1, val2});
}

int main()
{
    int i, j, k;

    scanf("%d%d", &N, &K);
    for(i=1; i<=N; i++) scanf("%lld", &P[i]);
    for(i=1; i<N; i++)
    {
        int u, v;
        scanf("%d%d", &u, &v);
        adj[u].push_back(v);
        adj[v].push_back(u);
    }

    if(K==0) return !printf("0");

    for(i=1; i<=N; i++)
    {
        for(j=1; j<=N; j++) S[j]=0;
        for(j=1; j<=N; j++) for(k=0; k<=K; k++) dp1[j][k]=0;
        dfs1(i, 0);
        ans=max(ans, dp1[i][K]);
    }
    //dfs1(1, 0);
    //dfs2(1, 0);
    //dfs3(1, 0);
    printf("%lld", ans);
}

Compilation message

chase.cpp: In function 'void dfs1(int, int)':
chase.cpp:17:12: warning: unused variable 'j' [-Wunused-variable]
     int i, j;
            ^
chase.cpp: In function 'void dfs2(int, int)':
chase.cpp:58:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for(j=0; j<V[i].size(); j++)
                      ~^~~~~~~~~~~~
chase.cpp:64:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for(j=0; j<V[i-1].size(); j++)
                      ~^~~~~~~~~~~~~~
chase.cpp: In function 'int main()':
chase.cpp:111:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d", &N, &K);
     ~~~~~^~~~~~~~~~~~~~~~
chase.cpp:112:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     for(i=1; i<=N; i++) scanf("%lld", &P[i]);
                         ~~~~~^~~~~~~~~~~~~~~
chase.cpp:116:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d", &u, &v);
         ~~~~~^~~~~~~~~~~~~~~~

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 2680 KB Output is correct
2 Correct 4 ms 2680 KB Output is correct
3 Correct 4 ms 2680 KB Output is correct
4 Correct 4 ms 2680 KB Output is correct
5 Correct 4 ms 2684 KB Output is correct
6 Correct 4 ms 2680 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 2680 KB Output is correct
2 Correct 4 ms 2680 KB Output is correct
3 Correct 4 ms 2680 KB Output is correct
4 Correct 4 ms 2680 KB Output is correct
5 Correct 4 ms 2684 KB Output is correct
6 Correct 4 ms 2680 KB Output is correct
7 Correct 525 ms 3688 KB Output is correct
8 Correct 57 ms 3680 KB Output is correct
9 Correct 51 ms 3576 KB Output is correct
10 Correct 531 ms 3704 KB Output is correct
11 Correct 201 ms 3576 KB Output is correct
12 Correct 75 ms 3576 KB Output is correct

Subtask #3
0 / 30.0

# Verdict Execution time Memory Grader output
1 Execution timed out 4038 ms 98168 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #4
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 2680 KB Output is correct
2 Correct 4 ms 2680 KB Output is correct
3 Correct 4 ms 2680 KB Output is correct
4 Correct 4 ms 2680 KB Output is correct
5 Correct 4 ms 2684 KB Output is correct
6 Correct 4 ms 2680 KB Output is correct
7 Correct 525 ms 3688 KB Output is correct
8 Correct 57 ms 3680 KB Output is correct
9 Correct 51 ms 3576 KB Output is correct
10 Correct 531 ms 3704 KB Output is correct
11 Correct 201 ms 3576 KB Output is correct
12 Correct 75 ms 3576 KB Output is correct
13 Execution timed out 4038 ms 98168 KB Time limit exceeded
14 Halted 0 ms 0 KB -