oj.uz

Submission #48301

# Submission time Handle Problem Language Result Execution time Memory
48301 2018-05-11T14:11:32 Z octopuses Beads and wires (APIO14_beads) C++17
100 / 100
 268 ms 20400 KB 
#include <bits/stdc++.h>

#define ll long long
#define fr first
#define sc second
#define M (ll)(3e17)

using namespace std;
const int N = 200020;

vector < pair < int, int > > G[N];
int n;
ll A[N], B[N], answer, par[N];

void go(int v, int p = 0)
{
  ll mx1 = -2e9, mx2 = -2e9, child = 0, tot = 0;
  for(int i = 0; i < G[v].size(); ++ i)
  {
    int to = G[v][i].first;
    if(to == p)
    {
      par[v] = G[v][i].second;
      swap(G[v][i], G[v].back());
      G[v].pop_back();
      i --;
      continue;
    }
    go(to, v);
    tot += A[to];
    child ++;
  }
  A[v] = B[v] = tot;
  for(int i = 0; i < G[v].size(); ++ i)
  {
    int to = G[v][i].first;
    if(to == p)
      continue;
    A[v] = max(A[v], tot - A[to] + B[to] + par[v] + G[v][i].second);
  }
}

void dfs(int v, ll a, ll b)
{
  ll tot = a;
  ll mx1, mx2;
  mx1 = b - a + par[v];
  mx2 = -2e9;
  for(int i = 0; i < G[v].size(); ++ i)
  {
    int to = G[v][i].first;
    tot += A[to];
    if(mx1 < B[to] - A[to] + G[v][i].second)
    {
      mx2 = mx1;
      mx1 = B[to] - A[to] + G[v][i].second;
    } else
      if(mx2 < B[to] - A[to] + G[v][i].second)
        mx2 = B[to] - A[to] + G[v][i].second;
  }
  answer = max(answer, tot);
  for(int i = 0; i < G[v].size(); ++ i)
  {
    int to = G[v][i].first;
    ll now = mx1;
    if(now == B[to] - A[to] + G[v][i].second)
      now = mx2;
    dfs(to, max(tot - A[to], now + tot - A[to] + G[v][i].second), tot - A[to]);
  }
}

int main()
{
  scanf("%d", &n);
  for(int i = 1; i < n; ++ i)
  {
    int x, y, val;
    scanf("%d %d %d", &x, &y, &val);
    G[x].push_back({y, val});
    G[y].push_back({x, val});
  }
  par[1] = -2e9;
  go(1);
  dfs(1, 0, 0);
  cout << answer << endl;
}

Compilation message

beads.cpp: In function 'void go(int, int)':
beads.cpp:18:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i = 0; i < G[v].size(); ++ i)
                  ~~^~~~~~~~~~~~~
beads.cpp:34:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i = 0; i < G[v].size(); ++ i)
                  ~~^~~~~~~~~~~~~
beads.cpp:17:6: warning: unused variable 'mx1' [-Wunused-variable]
   ll mx1 = -2e9, mx2 = -2e9, child = 0, tot = 0;
      ^~~
beads.cpp:17:18: warning: unused variable 'mx2' [-Wunused-variable]
   ll mx1 = -2e9, mx2 = -2e9, child = 0, tot = 0;
                  ^~~
beads.cpp: In function 'void dfs(int, long long int, long long int)':
beads.cpp:49:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i = 0; i < G[v].size(); ++ i)
                  ~~^~~~~~~~~~~~~
beads.cpp:62:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i = 0; i < G[v].size(); ++ i)
                  ~~^~~~~~~~~~~~~
beads.cpp: In function 'int main()':
beads.cpp:74:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &n);
   ~~~~~^~~~~~~~~~
beads.cpp:78:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d %d", &x, &y, &val);
     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 5120 KB Output is correct
2 Correct 6 ms 5120 KB Output is correct
3 Correct 6 ms 5120 KB Output is correct
4 Correct 5 ms 5120 KB Output is correct
5 Correct 7 ms 5120 KB Output is correct
6 Correct 6 ms 5120 KB Output is correct
7 Correct 5 ms 5120 KB Output is correct
8 Correct 6 ms 5120 KB Output is correct
9 Correct 5 ms 5120 KB Output is correct
10 Correct 6 ms 4992 KB Output is correct
11 Correct 6 ms 5120 KB Output is correct
12 Correct 5 ms 4992 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 5120 KB Output is correct
2 Correct 6 ms 5120 KB Output is correct
3 Correct 6 ms 5120 KB Output is correct
4 Correct 5 ms 5120 KB Output is correct
5 Correct 7 ms 5120 KB Output is correct
6 Correct 6 ms 5120 KB Output is correct
7 Correct 5 ms 5120 KB Output is correct
8 Correct 6 ms 5120 KB Output is correct
9 Correct 5 ms 5120 KB Output is correct
10 Correct 6 ms 4992 KB Output is correct
11 Correct 6 ms 5120 KB Output is correct
12 Correct 5 ms 4992 KB Output is correct
13 Correct 6 ms 4992 KB Output is correct
14 Correct 7 ms 5120 KB Output is correct
15 Correct 6 ms 4992 KB Output is correct
16 Correct 6 ms 5120 KB Output is correct
17 Correct 6 ms 4992 KB Output is correct
18 Correct 16 ms 4992 KB Output is correct
19 Correct 7 ms 5120 KB Output is correct
20 Correct 6 ms 5120 KB Output is correct
21 Correct 14 ms 5120 KB Output is correct
22 Correct 6 ms 4992 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 5120 KB Output is correct
2 Correct 6 ms 5120 KB Output is correct
3 Correct 6 ms 5120 KB Output is correct
4 Correct 5 ms 5120 KB Output is correct
5 Correct 7 ms 5120 KB Output is correct
6 Correct 6 ms 5120 KB Output is correct
7 Correct 5 ms 5120 KB Output is correct
8 Correct 6 ms 5120 KB Output is correct
9 Correct 5 ms 5120 KB Output is correct
10 Correct 6 ms 4992 KB Output is correct
11 Correct 6 ms 5120 KB Output is correct
12 Correct 5 ms 4992 KB Output is correct
13 Correct 6 ms 4992 KB Output is correct
14 Correct 7 ms 5120 KB Output is correct
15 Correct 6 ms 4992 KB Output is correct
16 Correct 6 ms 5120 KB Output is correct
17 Correct 6 ms 4992 KB Output is correct
18 Correct 16 ms 4992 KB Output is correct
19 Correct 7 ms 5120 KB Output is correct
20 Correct 6 ms 5120 KB Output is correct
21 Correct 14 ms 5120 KB Output is correct
22 Correct 6 ms 4992 KB Output is correct
23 Correct 9 ms 5376 KB Output is correct
24 Correct 9 ms 5376 KB Output is correct
25 Correct 8 ms 5376 KB Output is correct
26 Correct 12 ms 5632 KB Output is correct
27 Correct 13 ms 5632 KB Output is correct
28 Correct 11 ms 5760 KB Output is correct
29 Correct 11 ms 5632 KB Output is correct
30 Correct 11 ms 5632 KB Output is correct
31 Correct 12 ms 5888 KB Output is correct

Subtask #4
43.0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 5120 KB Output is correct
2 Correct 6 ms 5120 KB Output is correct
3 Correct 6 ms 5120 KB Output is correct
4 Correct 5 ms 5120 KB Output is correct
5 Correct 7 ms 5120 KB Output is correct
6 Correct 6 ms 5120 KB Output is correct
7 Correct 5 ms 5120 KB Output is correct
8 Correct 6 ms 5120 KB Output is correct
9 Correct 5 ms 5120 KB Output is correct
10 Correct 6 ms 4992 KB Output is correct
11 Correct 6 ms 5120 KB Output is correct
12 Correct 5 ms 4992 KB Output is correct
13 Correct 6 ms 4992 KB Output is correct
14 Correct 7 ms 5120 KB Output is correct
15 Correct 6 ms 4992 KB Output is correct
16 Correct 6 ms 5120 KB Output is correct
17 Correct 6 ms 4992 KB Output is correct
18 Correct 16 ms 4992 KB Output is correct
19 Correct 7 ms 5120 KB Output is correct
20 Correct 6 ms 5120 KB Output is correct
21 Correct 14 ms 5120 KB Output is correct
22 Correct 6 ms 4992 KB Output is correct
23 Correct 9 ms 5376 KB Output is correct
24 Correct 9 ms 5376 KB Output is correct
25 Correct 8 ms 5376 KB Output is correct
26 Correct 12 ms 5632 KB Output is correct
27 Correct 13 ms 5632 KB Output is correct
28 Correct 11 ms 5760 KB Output is correct
29 Correct 11 ms 5632 KB Output is correct
30 Correct 11 ms 5632 KB Output is correct
31 Correct 12 ms 5888 KB Output is correct
32 Correct 41 ms 8056 KB Output is correct
33 Correct 38 ms 8056 KB Output is correct
34 Correct 41 ms 8184 KB Output is correct
35 Correct 235 ms 17144 KB Output is correct
36 Correct 259 ms 17272 KB Output is correct
37 Correct 268 ms 17400 KB Output is correct
38 Correct 193 ms 17508 KB Output is correct
39 Correct 178 ms 17612 KB Output is correct
40 Correct 182 ms 17528 KB Output is correct
41 Correct 242 ms 20400 KB Output is correct