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Submission #198238

# Submission time Handle Problem Language Result Execution time Memory
198238 2020-01-25T08:21:04 Z mehrdad_sohrabi Beads and wires (APIO14_beads) C++14
57 / 100
 9 ms 1528 KB 
#include <bits/stdc++.h>
typedef int ll;
typedef long double ld;
#define pb push_back
#define pii pair < int, int >
#define F first
#define S second
//#define int long long int
#define sync ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0)

#define endl '\n'
using namespace std;
const int N=10002;
vector <pii> g[N];
ll vis[N];
ll ans=0;
ll dp[N][2];
void dfs(ll v,ll p,ll w){
    ll ma=-1e9;
    ll d=0;
    for (auto u : g[v]){
        if (u.F==p) continue;
        dfs(u.F,v,u.S);
        dp[v][1]+=dp[u.F][0];
        d+=dp[u.F][0];
        ma=max(ma,u.S+dp[u.F][1]-dp[u.F][0]);
    }
    if (p!=-1 && ma>-1e9){
        ll cnt=d+ma+w;
        dp[v][0]=max(dp[v][1],cnt);
    }
}
ll up[N][2];
ll dfs2(ll v,ll p){
    ll cnt=0,wp=0;
    for (auto u : g[v]){
        if (u.F==p){
            wp=u.S;
            continue;
        }
        cnt+=dp[u.F][0];
    }
    cnt+=up[v][0];
    for (auto u : g[v]){
        if (u.F==p) continue;
        up[u.F][1]=cnt-dp[u.F][0];
    }
    for (auto u : g[v]){
        if (u.F==p || v==1) continue;
        up[u.F][0]=max(up[u.F][0],u.S+wp+cnt-dp[u.F][0]-up[v][0]+up[v][1]);
    }
    ll mx=-1e9;
    for (auto u : g[v]){
        ll z=cnt;
        if (u.F==p) continue;
        /*
        for (auto q : g[v]){
            if (u.F==q.F || q.F==p) continue;
            ll t=z-dp[u.F][0]-dp[q.F][0]+dp[q.F][1]+u.S+q.S;
            up[u.F][0]=max(up[u.F][0],t);
        }
        */
        ll t=z+mx-dp[u.F][0]+u.S;
        up[u.F][0]=max(up[u.F][0],t);
        up[u.F][0]=max(up[u.F][0],up[u.F][1]);
        mx=max(mx,-dp[u.F][0]+dp[u.F][1]+u.S);
    }
    mx=-1e9;
    reverse(g[v].begin(),g[v].end());
    for (auto u : g[v]){
        ll z=cnt;
        if (u.F==p) continue;
        /*
        for (auto q : g[v]){
            if (u.F==q.F || q.F==p) continue;
            ll t=z-dp[u.F][0]-dp[q.F][0]+dp[q.F][1]+u.S+q.S;
            up[u.F][0]=max(up[u.F][0],t);
        }
        */
        ll t=z+mx-dp[u.F][0]+u.S;
        up[u.F][0]=max(up[u.F][0],t);
        up[u.F][0]=max(up[u.F][0],up[u.F][1]);
        mx=max(mx,-dp[u.F][0]+dp[u.F][1]+u.S);
    }
    for (auto u : g[v]){
        if (u.F!=p) dfs2(u.F,v);
    }
}
int32_t main(){
    sync;
    ll n;
    cin >> n;
    for (int i=0;i<n-1;i++){
        ll u,v,w;
        cin >> u >> v >> w;
        g[u].pb({v,w});
        g[v].pb({u,w});
    }
    for (int i=1;i<=n;i++){
        vector <pii> a;
        for (auto  q : g[i]){
           ll u=q.F;
            if (g[u].size()==1) a.pb({q.S,u});
        }
        sort(a.begin(),a.end());
        for (int j=1;j<a.size();j++){
            vis[a[j].S]=1;
        }
    }
    ll ma=0;
    ll cnt=0;
    dfs(1,-1,0);
    dfs2(1,1);
    for (int i=1;i<=n;i++){
        ma=max(ma,dp[i][1]+up[i][0]);
        //cout << i << " " << dp[i][1] << " " << up[i][0] << " " << ma << endl;
    }
    cout << ma << endl;
}
/*
10
4 10 2
1 2 21
1 3 13
6 7 1
7 9 5
2 4 3
2 5 8
1 6 55
6 8 34
*/
/*
6
1 2 20
2 3 20
3 4
10
3 5 10
3 6 10
*/

Compilation message

beads.cpp: In function 'll dfs2(ll, ll)':
beads.cpp:88:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^
beads.cpp: In function 'int32_t main()':
beads.cpp:106:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (int j=1;j<a.size();j++){
                      ~^~~~~~~~~
beads.cpp:111:8: warning: unused variable 'cnt' [-Wunused-variable]
     ll cnt=0;
        ^~~

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 632 KB Output is correct
2 Correct 3 ms 632 KB Output is correct
3 Correct 2 ms 636 KB Output is correct
4 Correct 7 ms 660 KB Output is correct
5 Correct 2 ms 504 KB Output is correct
6 Correct 2 ms 504 KB Output is correct
7 Correct 3 ms 632 KB Output is correct
8 Correct 0 ms 504 KB Output is correct
9 Correct 3 ms 632 KB Output is correct
10 Correct 2 ms 504 KB Output is correct
11 Correct 2 ms 504 KB Output is correct
12 Correct 2 ms 632 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 632 KB Output is correct
2 Correct 3 ms 632 KB Output is correct
3 Correct 2 ms 636 KB Output is correct
4 Correct 7 ms 660 KB Output is correct
5 Correct 2 ms 504 KB Output is correct
6 Correct 2 ms 504 KB Output is correct
7 Correct 3 ms 632 KB Output is correct
8 Correct 0 ms 504 KB Output is correct
9 Correct 3 ms 632 KB Output is correct
10 Correct 2 ms 504 KB Output is correct
11 Correct 2 ms 504 KB Output is correct
12 Correct 2 ms 632 KB Output is correct
13 Correct 2 ms 632 KB Output is correct
14 Correct 2 ms 632 KB Output is correct
15 Correct 2 ms 504 KB Output is correct
16 Correct 2 ms 632 KB Output is correct
17 Correct 2 ms 632 KB Output is correct
18 Correct 2 ms 632 KB Output is correct
19 Correct 2 ms 632 KB Output is correct
20 Correct 2 ms 632 KB Output is correct
21 Correct 2 ms 632 KB Output is correct
22 Correct 2 ms 632 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 632 KB Output is correct
2 Correct 3 ms 632 KB Output is correct
3 Correct 2 ms 636 KB Output is correct
4 Correct 7 ms 660 KB Output is correct
5 Correct 2 ms 504 KB Output is correct
6 Correct 2 ms 504 KB Output is correct
7 Correct 3 ms 632 KB Output is correct
8 Correct 0 ms 504 KB Output is correct
9 Correct 3 ms 632 KB Output is correct
10 Correct 2 ms 504 KB Output is correct
11 Correct 2 ms 504 KB Output is correct
12 Correct 2 ms 632 KB Output is correct
13 Correct 2 ms 632 KB Output is correct
14 Correct 2 ms 632 KB Output is correct
15 Correct 2 ms 504 KB Output is correct
16 Correct 2 ms 632 KB Output is correct
17 Correct 2 ms 632 KB Output is correct
18 Correct 2 ms 632 KB Output is correct
19 Correct 2 ms 632 KB Output is correct
20 Correct 2 ms 632 KB Output is correct
21 Correct 2 ms 632 KB Output is correct
22 Correct 2 ms 632 KB Output is correct
23 Correct 5 ms 888 KB Output is correct
24 Correct 4 ms 888 KB Output is correct
25 Correct 6 ms 760 KB Output is correct
26 Correct 9 ms 1144 KB Output is correct
27 Correct 9 ms 1144 KB Output is correct
28 Correct 9 ms 1332 KB Output is correct
29 Correct 9 ms 1144 KB Output is correct
30 Correct 8 ms 1272 KB Output is correct
31 Correct 9 ms 1528 KB Output is correct

Subtask #4
0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 632 KB Output is correct
2 Correct 3 ms 632 KB Output is correct
3 Correct 2 ms 636 KB Output is correct
4 Correct 7 ms 660 KB Output is correct
5 Correct 2 ms 504 KB Output is correct
6 Correct 2 ms 504 KB Output is correct
7 Correct 3 ms 632 KB Output is correct
8 Correct 0 ms 504 KB Output is correct
9 Correct 3 ms 632 KB Output is correct
10 Correct 2 ms 504 KB Output is correct
11 Correct 2 ms 504 KB Output is correct
12 Correct 2 ms 632 KB Output is correct
13 Correct 2 ms 632 KB Output is correct
14 Correct 2 ms 632 KB Output is correct
15 Correct 2 ms 504 KB Output is correct
16 Correct 2 ms 632 KB Output is correct
17 Correct 2 ms 632 KB Output is correct
18 Correct 2 ms 632 KB Output is correct
19 Correct 2 ms 632 KB Output is correct
20 Correct 2 ms 632 KB Output is correct
21 Correct 2 ms 632 KB Output is correct
22 Correct 2 ms 632 KB Output is correct
23 Correct 5 ms 888 KB Output is correct
24 Correct 4 ms 888 KB Output is correct
25 Correct 6 ms 760 KB Output is correct
26 Correct 9 ms 1144 KB Output is correct
27 Correct 9 ms 1144 KB Output is correct
28 Correct 9 ms 1332 KB Output is correct
29 Correct 9 ms 1144 KB Output is correct
30 Correct 8 ms 1272 KB Output is correct
31 Correct 9 ms 1528 KB Output is correct
32 Runtime error 3 ms 888 KB Execution killed with signal 11 (could be triggered by violating memory limits)
33 Halted 0 ms 0 KB -