oj.uz

Submission #235551

# Submission time Handle Problem Language Result Execution time Memory
235551 2020-05-28T13:56:18 Z Autoratch Beads and wires (APIO14_beads) C++14
100 / 100
 214 ms 23792 KB 
#include <bits/stdc++.h>
using namespace std;

const int N = 2e5 + 1;

int n;
vector<pair<int,int> > adj[N];
int a[N][4];

void dfs(int u,int p)
{
    a[u][1] = -1e9;
    a[u][3] = -1e9;
    int m3 = -1e9,m21 = -1e9,m22 = -1e9,m01 = -1e9,m02 = -1e9,dis = -1e9,v2,v0;
    for(auto [d,v] : adj[u]) if(v!=p)
    {
        dfs(v,u); 
        int each = a[v][0],ez = a[v][1]+d;
        a[u][0]+=max(each,ez);
 
        a[u][1] = max(a[u][1],a[v][0]+d-max(each,ez));
        
        m3 = max(m3,a[v][3]+d-max(each,ez));
        
        dis = max(dis,a[v][2]-max(each,ez));

        if(a[v][2]+d-max(each,ez)>m21) m22 = m21,m21 = a[v][2]+d-max(each,ez),v2 = v;
        else if(a[v][2]+d-max(each,ez)>m22) m22 = a[v][2]+d-max(each,ez);

        if(a[v][0]+d-max(each,ez)>m01) m02 = m01,m01 = a[v][0]+d-max(each,ez),v0 = v;
        else if(a[v][0]+d-max(each,ez)>m02) m02 = a[v][0]+d-max(each,ez);

        a[u][3] = max(a[u][3],a[v][2]+d-max(each,ez));
    }
    a[u][1]+=a[u][0];
    a[u][3]+=a[u][0];
    if(m01!=-1e9 and m02!=-1e9) a[u][2] = max(a[u][2],m01+m02);
    if(m01!=-1e9 and m21!=-1e9 and v2!=v0) a[u][2] = max(a[u][2],m01+m21);
    if(m02!=-1e9 and m21!=-1e9) a[u][2] = max(a[u][2],m02+m21);
    if(m01!=-1e9 and m22!=-1e9) a[u][2] = max(a[u][2],m01+m22);
    a[u][2] = max(a[u][2],m3);
    a[u][2] = max(a[u][2],dis);
    a[u][2]+=a[u][0];
    
/*
    if(u==1)
    {
        cout << m01 << ' ' << m02 << ' ' << m21 << ' ' << m22 << endl;
    }
    
    cout << u << endl;
    for(int i = 0;i < 4;i++) cout << a[u][i] << ' ';
    cout << endl;
*/
}

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

    cin >> n;
    for(int i = 0;i < n-1;i++)
    {
        int a,b,d;
        cin >> a >> b >> d;
        adj[a].push_back({d,b});
        adj[b].push_back({d,a});
    }
    dfs(1,0);
    cout << max(a[1][0],a[1][2]);
}

Compilation message

beads.cpp: In function 'void dfs(int, int)':
beads.cpp:15:14: warning: decomposition declaration only available with -std=c++1z or -std=gnu++1z
     for(auto [d,v] : adj[u]) if(v!=p)
              ^
beads.cpp:38:32: warning: 'v0' may be used uninitialized in this function [-Wmaybe-uninitialized]
     if(m01!=-1e9 and m21!=-1e9 and v2!=v0) a[u][2] = max(a[u][2],m01+m21);
        ~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~
beads.cpp:38:32: warning: 'v2' may be used uninitialized in this function [-Wmaybe-uninitialized]

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 4992 KB Output is correct
2 Correct 7 ms 4992 KB Output is correct
3 Correct 8 ms 4992 KB Output is correct
4 Correct 7 ms 4992 KB Output is correct
5 Correct 7 ms 4992 KB Output is correct
6 Correct 7 ms 5120 KB Output is correct
7 Correct 7 ms 4992 KB Output is correct
8 Correct 7 ms 5120 KB Output is correct
9 Correct 7 ms 4992 KB Output is correct
10 Correct 7 ms 4992 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 7 ms 4992 KB Output is correct
3 Correct 8 ms 4992 KB Output is correct
4 Correct 7 ms 4992 KB Output is correct
5 Correct 7 ms 4992 KB Output is correct
6 Correct 7 ms 5120 KB Output is correct
7 Correct 7 ms 4992 KB Output is correct
8 Correct 7 ms 5120 KB Output is correct
9 Correct 7 ms 4992 KB Output is correct
10 Correct 7 ms 4992 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 8 ms 4992 KB Output is correct
15 Correct 7 ms 4992 KB Output is correct
16 Correct 7 ms 4992 KB Output is correct
17 Correct 7 ms 4992 KB Output is correct
18 Correct 7 ms 4992 KB Output is correct
19 Correct 7 ms 4992 KB Output is correct
20 Correct 7 ms 5120 KB Output is correct
21 Correct 7 ms 4992 KB Output is correct
22 Correct 7 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 7 ms 4992 KB Output is correct
3 Correct 8 ms 4992 KB Output is correct
4 Correct 7 ms 4992 KB Output is correct
5 Correct 7 ms 4992 KB Output is correct
6 Correct 7 ms 5120 KB Output is correct
7 Correct 7 ms 4992 KB Output is correct
8 Correct 7 ms 5120 KB Output is correct
9 Correct 7 ms 4992 KB Output is correct
10 Correct 7 ms 4992 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 8 ms 4992 KB Output is correct
15 Correct 7 ms 4992 KB Output is correct
16 Correct 7 ms 4992 KB Output is correct
17 Correct 7 ms 4992 KB Output is correct
18 Correct 7 ms 4992 KB Output is correct
19 Correct 7 ms 4992 KB Output is correct
20 Correct 7 ms 5120 KB Output is correct
21 Correct 7 ms 4992 KB Output is correct
22 Correct 7 ms 4992 KB Output is correct
23 Correct 10 ms 5376 KB Output is correct
24 Correct 10 ms 5376 KB Output is correct
25 Correct 10 ms 5376 KB Output is correct
26 Correct 12 ms 5760 KB Output is correct
27 Correct 12 ms 5760 KB Output is correct
28 Correct 11 ms 5760 KB Output is correct
29 Correct 12 ms 5760 KB Output is correct
30 Correct 12 ms 5760 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 7 ms 4992 KB Output is correct
3 Correct 8 ms 4992 KB Output is correct
4 Correct 7 ms 4992 KB Output is correct
5 Correct 7 ms 4992 KB Output is correct
6 Correct 7 ms 5120 KB Output is correct
7 Correct 7 ms 4992 KB Output is correct
8 Correct 7 ms 5120 KB Output is correct
9 Correct 7 ms 4992 KB Output is correct
10 Correct 7 ms 4992 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 8 ms 4992 KB Output is correct
15 Correct 7 ms 4992 KB Output is correct
16 Correct 7 ms 4992 KB Output is correct
17 Correct 7 ms 4992 KB Output is correct
18 Correct 7 ms 4992 KB Output is correct
19 Correct 7 ms 4992 KB Output is correct
20 Correct 7 ms 5120 KB Output is correct
21 Correct 7 ms 4992 KB Output is correct
22 Correct 7 ms 4992 KB Output is correct
23 Correct 10 ms 5376 KB Output is correct
24 Correct 10 ms 5376 KB Output is correct
25 Correct 10 ms 5376 KB Output is correct
26 Correct 12 ms 5760 KB Output is correct
27 Correct 12 ms 5760 KB Output is correct
28 Correct 11 ms 5760 KB Output is correct
29 Correct 12 ms 5760 KB Output is correct
30 Correct 12 ms 5760 KB Output is correct
31 Correct 12 ms 6144 KB Output is correct
32 Correct 36 ms 8440 KB Output is correct
33 Correct 38 ms 8448 KB Output is correct
34 Correct 41 ms 8440 KB Output is correct
35 Correct 202 ms 19068 KB Output is correct
36 Correct 214 ms 19192 KB Output is correct
37 Correct 186 ms 19192 KB Output is correct
38 Correct 137 ms 19560 KB Output is correct
39 Correct 140 ms 19544 KB Output is correct
40 Correct 136 ms 19560 KB Output is correct
41 Correct 175 ms 23792 KB Output is correct