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Submission #41620

# Submission time Handle Problem Language Result Execution time Memory
41620 2018-02-20T03:04:29 Z funcsr Beads and wires (APIO14_beads) C++14
100 / 100
 396 ms 28648 KB 
#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <cassert>
using namespace std;
#define int long long
typedef pair<int, int> P;
#define rep(i, n) for (int i=0; i<(n); i++)
#define all(x) x.begin(), x.end()
#define uniq(x) x.erase(unique(all(x)), x.end())
#define index(x, y) (int)(lower_bound(all(x), y) - x.begin())
#define _1 first
#define _2 second
#define pb push_back
//#define INF 2100000000
#define INF (1LL<<40)

int N;
vector<P> G[200000];
P dp[200000][3];
void update(int x, int v, int s) {
  if (P(v, s) > dp[x][1]) dp[x][2] = dp[x][1], dp[x][1] = P(v, s);
  else if (P(v, s) > dp[x][2]) dp[x][2] = P(v, s);
}
int get(int x, int s=-2) { return dp[x][1+(dp[x][1]._2==s)]._1; }

void dfs(int x, int p) {
  dp[x][0] = P(0, -1);
  dp[x][1] = P(-INF, -1);
  dp[x][2] = P(-INF, -1);
  for (P pp : G[x]) if (pp._1 != p) {
    int t = pp._1, len = pp._2;
    dfs(t, x);
    int v = max(dp[t][0]._1, dp[t][1]._1+len);
    dp[x][0]._1 += v;
  }
  for (P pp : G[x]) if (pp._1 != p) {
    int t = pp._1, len = pp._2;
    int v = max(dp[t][0]._1, dp[t][1]._1+len);
    update(x, dp[x][0]._1-v + dp[t][0]._1+len, t);
  }
}

void dfs2(int x, int p, int plen, int diff) {
  if (p != -1) {
    int pv = max(plen + get(p, x) - diff, dp[p][0]._1 - diff);
    for (int k=1; k<=2; k++) if (dp[x][k]._1 != -INF) dp[x][k]._1 += pv;
    update(x, dp[x][0]._1 + plen + dp[p][0]._1 - diff, p);
    int old =dp[x][0]._1;
    dp[x][0]._1 += pv;
  }
  for (P pp : G[x]) if (pp._1 != p) {
    int t = pp._1, len = pp._2;
    dfs2(t, x, len, max(dp[t][0]._1, dp[t][1]._1+len));
  }
}

signed main() {
  cin >> N;
  rep(i, N-1) {
    int a, b, c;
    cin >> a >> b >> c;
    a--, b--;
    G[a].pb(P(b, c));
    G[b].pb(P(a, c));
  }
  dfs(0, -1);
  dfs2(0, -1, 0, 0);
  int m = 0;
  rep(i, N) m = max(m, dp[i][0]._1);
  cout << m << "\n";
  return 0;
}

Compilation message

beads.cpp: In function 'void dfs2(long long int, long long int, long long int, long long int)':
beads.cpp:50:9: warning: unused variable 'old' [-Wunused-variable]
     int old =dp[x][0]._1;
         ^~~

Subtask #1
13.0 / 13.0

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

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 4992 KB Output is correct
2 Correct 6 ms 4992 KB Output is correct
3 Correct 6 ms 4992 KB Output is correct
4 Correct 6 ms 4992 KB Output is correct
5 Correct 6 ms 4992 KB Output is correct
6 Correct 5 ms 4992 KB Output is correct
7 Correct 5 ms 4992 KB Output is correct
8 Correct 6 ms 5120 KB Output is correct
9 Correct 5 ms 4992 KB Output is correct
10 Correct 5 ms 4992 KB Output is correct
11 Correct 6 ms 4992 KB Output is correct
12 Correct 6 ms 4992 KB Output is correct
13 Correct 6 ms 4992 KB Output is correct
14 Correct 6 ms 4992 KB Output is correct
15 Correct 6 ms 4992 KB Output is correct
16 Correct 6 ms 4992 KB Output is correct
17 Correct 6 ms 4992 KB Output is correct
18 Correct 6 ms 4992 KB Output is correct
19 Correct 6 ms 5120 KB Output is correct
20 Correct 6 ms 4992 KB Output is correct
21 Correct 6 ms 4992 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 5 ms 4992 KB Output is correct
2 Correct 6 ms 4992 KB Output is correct
3 Correct 6 ms 4992 KB Output is correct
4 Correct 6 ms 4992 KB Output is correct
5 Correct 6 ms 4992 KB Output is correct
6 Correct 5 ms 4992 KB Output is correct
7 Correct 5 ms 4992 KB Output is correct
8 Correct 6 ms 5120 KB Output is correct
9 Correct 5 ms 4992 KB Output is correct
10 Correct 5 ms 4992 KB Output is correct
11 Correct 6 ms 4992 KB Output is correct
12 Correct 6 ms 4992 KB Output is correct
13 Correct 6 ms 4992 KB Output is correct
14 Correct 6 ms 4992 KB Output is correct
15 Correct 6 ms 4992 KB Output is correct
16 Correct 6 ms 4992 KB Output is correct
17 Correct 6 ms 4992 KB Output is correct
18 Correct 6 ms 4992 KB Output is correct
19 Correct 6 ms 5120 KB Output is correct
20 Correct 6 ms 4992 KB Output is correct
21 Correct 6 ms 4992 KB Output is correct
22 Correct 6 ms 4992 KB Output is correct
23 Correct 10 ms 5504 KB Output is correct
24 Correct 11 ms 5532 KB Output is correct
25 Correct 11 ms 5504 KB Output is correct
26 Correct 16 ms 6016 KB Output is correct
27 Correct 17 ms 5988 KB Output is correct
28 Correct 16 ms 6012 KB Output is correct
29 Correct 15 ms 5888 KB Output is correct
30 Correct 17 ms 6016 KB Output is correct
31 Correct 17 ms 6400 KB Output is correct

Subtask #4
43.0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 4992 KB Output is correct
2 Correct 6 ms 4992 KB Output is correct
3 Correct 6 ms 4992 KB Output is correct
4 Correct 6 ms 4992 KB Output is correct
5 Correct 6 ms 4992 KB Output is correct
6 Correct 5 ms 4992 KB Output is correct
7 Correct 5 ms 4992 KB Output is correct
8 Correct 6 ms 5120 KB Output is correct
9 Correct 5 ms 4992 KB Output is correct
10 Correct 5 ms 4992 KB Output is correct
11 Correct 6 ms 4992 KB Output is correct
12 Correct 6 ms 4992 KB Output is correct
13 Correct 6 ms 4992 KB Output is correct
14 Correct 6 ms 4992 KB Output is correct
15 Correct 6 ms 4992 KB Output is correct
16 Correct 6 ms 4992 KB Output is correct
17 Correct 6 ms 4992 KB Output is correct
18 Correct 6 ms 4992 KB Output is correct
19 Correct 6 ms 5120 KB Output is correct
20 Correct 6 ms 4992 KB Output is correct
21 Correct 6 ms 4992 KB Output is correct
22 Correct 6 ms 4992 KB Output is correct
23 Correct 10 ms 5504 KB Output is correct
24 Correct 11 ms 5532 KB Output is correct
25 Correct 11 ms 5504 KB Output is correct
26 Correct 16 ms 6016 KB Output is correct
27 Correct 17 ms 5988 KB Output is correct
28 Correct 16 ms 6012 KB Output is correct
29 Correct 15 ms 5888 KB Output is correct
30 Correct 17 ms 6016 KB Output is correct
31 Correct 17 ms 6400 KB Output is correct
32 Correct 77 ms 9976 KB Output is correct
33 Correct 71 ms 9976 KB Output is correct
34 Correct 119 ms 10076 KB Output is correct
35 Correct 389 ms 24684 KB Output is correct
36 Correct 368 ms 24696 KB Output is correct
37 Correct 375 ms 24824 KB Output is correct
38 Correct 308 ms 24112 KB Output is correct
39 Correct 307 ms 23896 KB Output is correct
40 Correct 333 ms 23844 KB Output is correct
41 Correct 396 ms 28648 KB Output is correct