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Submission #143306

# Submission time Handle Problem Language Result Execution time Memory
143306 2019-08-13T15:27:33 Z Milki Chase (CEOI17_chase) C++14
100 / 100
 1228 ms 335268 KB 
#include<bits/stdc++.h>
using namespace std;

#define FOR(i, a, b) for(int i = a; i < b; ++i)
#define REP(i, n) FOR(i, 0, n)
#define _ << " " <<
#define sz(x) ((int) x.size())
#define pb(x) push_back(x)
#define TRACE(x) cerr << #x << " = " << x << endl

typedef long long ll;
typedef pair<ll, ll> point;

const int MAXN = 1e5 + 5, MAXV = 105;
const ll inf = 1e16;

int n, k, val[MAXN];
vector <int> E[MAXN];
ll dp_down[MAXV][MAXN], sum[MAXN], sol, dp_up[MAXV][MAXN];

struct Best{
  point a, b;
  Best(){
    a = point(0, MAXN - 1);
    b = point(0, MAXN - 1);
  }
  void ubaci(point x){
    if(x.first > a.first){
      if(x.second != a.second)
        b = a;

      a = x;
    }
    else if(x.first > b.first){
      if(x.second != a.second)
        b = x;
    }
  }
};

void dfs(int x, int p = -1){
  vector <Best> mx1, mx2;
  mx1.resize(k + 1); mx2.resize(k + 1);

  dp_up[1][x] = sum[x];
  mx1[1].ubaci( {sum[x], -1} );

  for(auto e : E[x]){
    if(e == p) continue;

    dfs(e, x);
    FOR(i, 1, k + 1){
      ll ans = dp_down[i - 1][e] + sum[e] - val[x];
      ans = max(ans, dp_down[i][e]);

      if(ans > dp_down[i][x]){
        dp_down[i][x] = ans;
      }
      mx2[i].ubaci(point(ans, e));

      dp_down[i][x] = max(dp_down[i][x], dp_down[i - 1][x]);

      ans = dp_up[i - 1][e] + sum[x] - val[e];
      ans = max(ans, dp_up[i][e]);

      if(ans > dp_up[i][x]){
        dp_up[i][x] = ans;
      }
      mx1[i].ubaci(point(ans, e));

      dp_up[i][x] = max(dp_up[i][x], dp_up[i - 1][x]);

      mx1[i].ubaci(mx1[i - 1].a);
      mx1[i].ubaci(mx1[i - 1].b);

      mx2[i].ubaci(mx2[i - 1].a);
      mx2[i].ubaci(mx2[i - 1].b);
    }
  }

  REP(i, k + 1){
    if(mx1[i].a.second == mx2[k - i].a.second){
      sol = max(sol, mx1[i].a.first + mx2[k - i].b.first);
      sol = max(sol, mx1[i].b.first + mx2[k - i].a.first);
    }
    else{
      sol = max(sol, mx1[i].a.first + mx2[k - i].a.first);
    }
  }

}

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

  cin >> n >> k;
  REP(i, n)
    cin >> val[i];
  REP(i, n - 1){
    int a, b; cin >> a >> b; a --; b --;
    E[a].pb(b); E[b].pb(a);
  }

  if(k == 0){
    cout << 0;
    return 0;
  }

  REP(i, n){
    for(auto e : E[i])
      sum[i] += val[e];
    sol = max(sol, sum[i]);
  }

  dfs(0);

  cout << sol;
}

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 2808 KB Output is correct
2 Correct 4 ms 2808 KB Output is correct
3 Correct 4 ms 2680 KB Output is correct
4 Correct 4 ms 2812 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 5 ms 2808 KB Output is correct
2 Correct 4 ms 2808 KB Output is correct
3 Correct 4 ms 2680 KB Output is correct
4 Correct 4 ms 2812 KB Output is correct
5 Correct 4 ms 2684 KB Output is correct
6 Correct 4 ms 2680 KB Output is correct
7 Correct 30 ms 7160 KB Output is correct
8 Correct 6 ms 3128 KB Output is correct
9 Correct 6 ms 2984 KB Output is correct
10 Correct 11 ms 5496 KB Output is correct
11 Correct 7 ms 3576 KB Output is correct
12 Correct 6 ms 3064 KB Output is correct

Subtask #3
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1049 ms 332784 KB Output is correct
2 Correct 1047 ms 330964 KB Output is correct
3 Correct 325 ms 10504 KB Output is correct
4 Correct 109 ms 9080 KB Output is correct
5 Correct 1170 ms 162844 KB Output is correct
6 Correct 1223 ms 164488 KB Output is correct
7 Correct 1228 ms 164192 KB Output is correct

Subtask #4
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 2808 KB Output is correct
2 Correct 4 ms 2808 KB Output is correct
3 Correct 4 ms 2680 KB Output is correct
4 Correct 4 ms 2812 KB Output is correct
5 Correct 4 ms 2684 KB Output is correct
6 Correct 4 ms 2680 KB Output is correct
7 Correct 30 ms 7160 KB Output is correct
8 Correct 6 ms 3128 KB Output is correct
9 Correct 6 ms 2984 KB Output is correct
10 Correct 11 ms 5496 KB Output is correct
11 Correct 7 ms 3576 KB Output is correct
12 Correct 6 ms 3064 KB Output is correct
13 Correct 1049 ms 332784 KB Output is correct
14 Correct 1047 ms 330964 KB Output is correct
15 Correct 325 ms 10504 KB Output is correct
16 Correct 109 ms 9080 KB Output is correct
17 Correct 1170 ms 162844 KB Output is correct
18 Correct 1223 ms 164488 KB Output is correct
19 Correct 1228 ms 164192 KB Output is correct
20 Correct 1189 ms 164392 KB Output is correct
21 Correct 67 ms 6776 KB Output is correct
22 Correct 1164 ms 164268 KB Output is correct
23 Correct 109 ms 9136 KB Output is correct
24 Correct 1170 ms 164336 KB Output is correct
25 Correct 308 ms 9920 KB Output is correct
26 Correct 1079 ms 335216 KB Output is correct
27 Correct 1091 ms 335268 KB Output is correct