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Submission #240886

# Submission time Handle Problem Language Result Execution time Memory
240886 2020-06-21T11:43:38 Z nvmdava Beads and wires (APIO14_beads) C++17
100 / 100
 264 ms 25532 KB 
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ff first
#define ss second
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
#define N 200005
const ll MOD = 1000000007;
const int INF = 0x3f3f3f3f;

vector<pair<int, int> > adj[N];

ll ans = 0;

ll dp[N][2][2];

void dfs1(int v, int p = 0, int d = 0){
    for(auto& x : adj[v]){
        if(x.ff == p) continue;
        dfs1(x.ff, v, x.ss);
    }
    ll mx = 0;
    for(auto& x : adj[v]){
        if(x.ff == p) continue;
        dp[v][0][0] += dp[x.ff][0][1];
        mx = max(mx, d + dp[x.ff][0][0] + x.ss - dp[x.ff][0][1]);
    }
    if(p == 0) mx = 0;
    dp[v][0][1] = dp[v][0][0] + mx;
    ans = max(ans, dp[v][0][1]);
}

void dfs2(int v, int p = 0, ll d = 0){
    ll t = dp[v][1][1];

    ll mx1 = (p == 0 ? -99999999999 : d + dp[v][1][0] - dp[v][1][1]), mx2 = -9999999999999;
    for(auto& x : adj[v]){
        if(x.ff == p) continue;
        t += dp[x.ff][0][1];
        ll w = x.ss + dp[x.ff][0][0] - dp[x.ff][0][1];
        if(w > mx1){
            mx2 = mx1;
            mx1 = w;
        } else mx2 = max(mx2, w);
    }

    for(auto& x : adj[v]){
        if(x.ff == p) continue;
        dp[x.ff][1][0] = t - dp[x.ff][0][1];
        ll w = x.ss + dp[x.ff][0][0] - dp[x.ff][0][1];
        dp[x.ff][1][1] = dp[x.ff][1][0] + max(0LL, x.ss + (w == mx1 ? mx2 : mx1));
        ans = max(ans, dp[x.ff][1][1]);
        dfs2(x.ff, v, x.ss);
    }
}

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    int n;
    cin>>n;
    for(int x, y, z, i = 1; i < n; ++i){
        cin>>x>>y>>z;
        adj[x].push_back({y, z});
        adj[y].push_back({x, z});
    }
    dfs1(1);
    dfs2(1);

    cout<<ans;

}

Subtask #1
13.0 / 13.0

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

Subtask #2
15.0 / 15.0

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

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 4992 KB Output is correct
2 Correct 8 ms 4992 KB Output is correct
3 Correct 8 ms 4992 KB Output is correct
4 Correct 8 ms 4992 KB Output is correct
5 Correct 7 ms 4992 KB Output is correct
6 Correct 7 ms 4992 KB Output is correct
7 Correct 8 ms 4992 KB Output is correct
8 Correct 8 ms 4992 KB Output is correct
9 Correct 7 ms 5120 KB Output is correct
10 Correct 8 ms 5120 KB Output is correct
11 Correct 7 ms 4992 KB Output is correct
12 Correct 7 ms 5120 KB Output is correct
13 Correct 7 ms 4992 KB Output is correct
14 Correct 7 ms 5120 KB Output is correct
15 Correct 8 ms 4992 KB Output is correct
16 Correct 8 ms 4992 KB Output is correct
17 Correct 7 ms 5120 KB Output is correct
18 Correct 8 ms 4992 KB Output is correct
19 Correct 7 ms 5120 KB Output is correct
20 Correct 8 ms 4992 KB Output is correct
21 Correct 8 ms 5120 KB Output is correct
22 Correct 8 ms 4992 KB Output is correct
23 Correct 10 ms 5504 KB Output is correct
24 Correct 10 ms 5504 KB Output is correct
25 Correct 10 ms 5504 KB Output is correct
26 Correct 13 ms 5888 KB Output is correct
27 Correct 13 ms 5888 KB Output is correct
28 Correct 11 ms 5888 KB Output is correct
29 Correct 12 ms 5888 KB Output is correct
30 Correct 12 ms 5888 KB Output is correct
31 Correct 12 ms 6144 KB Output is correct

Subtask #4
43.0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 4992 KB Output is correct
2 Correct 8 ms 4992 KB Output is correct
3 Correct 8 ms 4992 KB Output is correct
4 Correct 8 ms 4992 KB Output is correct
5 Correct 7 ms 4992 KB Output is correct
6 Correct 7 ms 4992 KB Output is correct
7 Correct 8 ms 4992 KB Output is correct
8 Correct 8 ms 4992 KB Output is correct
9 Correct 7 ms 5120 KB Output is correct
10 Correct 8 ms 5120 KB Output is correct
11 Correct 7 ms 4992 KB Output is correct
12 Correct 7 ms 5120 KB Output is correct
13 Correct 7 ms 4992 KB Output is correct
14 Correct 7 ms 5120 KB Output is correct
15 Correct 8 ms 4992 KB Output is correct
16 Correct 8 ms 4992 KB Output is correct
17 Correct 7 ms 5120 KB Output is correct
18 Correct 8 ms 4992 KB Output is correct
19 Correct 7 ms 5120 KB Output is correct
20 Correct 8 ms 4992 KB Output is correct
21 Correct 8 ms 5120 KB Output is correct
22 Correct 8 ms 4992 KB Output is correct
23 Correct 10 ms 5504 KB Output is correct
24 Correct 10 ms 5504 KB Output is correct
25 Correct 10 ms 5504 KB Output is correct
26 Correct 13 ms 5888 KB Output is correct
27 Correct 13 ms 5888 KB Output is correct
28 Correct 11 ms 5888 KB Output is correct
29 Correct 12 ms 5888 KB Output is correct
30 Correct 12 ms 5888 KB Output is correct
31 Correct 12 ms 6144 KB Output is correct
32 Correct 41 ms 9208 KB Output is correct
33 Correct 39 ms 9208 KB Output is correct
34 Correct 38 ms 9216 KB Output is correct
35 Correct 264 ms 22264 KB Output is correct
36 Correct 235 ms 22328 KB Output is correct
37 Correct 220 ms 22264 KB Output is correct
38 Correct 148 ms 22756 KB Output is correct
39 Correct 148 ms 22740 KB Output is correct
40 Correct 153 ms 22624 KB Output is correct
41 Correct 215 ms 25532 KB Output is correct