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Submission #732874

# Submission time Handle Problem Language Result Execution time Memory
732874 2023-04-29T11:08:57 Z vjudge1 Beads and wires (APIO14_beads) C++17
100 / 100
 231 ms 30100 KB 
#include<bits/stdc++.h>
using namespace std;
#define all(fl) fl.begin(),fl.end()
#define pb push_back
#define fi first
#define se second
#define for1(i,j,k) for(int i=j;i<=k;i++)
#define for2(i,j,k) for(int i=j;i>=k;i--)
#define for3(i,j,k,l) for(int i=j;i<=k;i+=l)
#define lb lower_bound
#define ub upper_bound
#define sz(a) (int)a.size()
#define gcd __gcd
#define lcm(x,y) x*y/__gcd(x,y)
using pii=pair<int,int>;
using pli=pair<long long,int>;
const int maxn=2e5+9;
vector<pii>a[maxn];
int p[maxn];
const long long inf=-2e9-7;
long long dp[maxn][2];
long long cop[maxn][2];
void dfs1(int u,int par){
p[u]=par;
dp[u][1]=inf;
dp[u][0]=0;
for (auto &v:a[u]){
    if (v.fi==par){
        swap(v,a[u][0]);
    }
}
for (auto v:a[u]){
    if (v.fi==par)continue;
    dfs1(v.fi,u);
    dp[u][0]+=max(dp[v.fi][1]+v.se,dp[v.fi][0]);
}
long long choose=inf,notchoose=0;
for (auto v:a[u]){
    if (v.fi==par)continue;
    choose=max(choose+max(dp[v.fi][0],dp[v.fi][1]+v.se),notchoose+dp[v.fi][0]+v.se);
    notchoose=notchoose+max(dp[v.fi][0],dp[v.fi][1]+v.se);
}
dp[u][1]=choose;
cop[u][0]=dp[u][0];
cop[u][1]=dp[u][1];
}
long long ans=0;
long long f[3];
long long g[maxn][2];
void reroot(int u,int par){
dp[u][0]=0;
dp[u][1]=inf;
for (auto v:a[u]){
    dp[u][0]+=max(dp[v.fi][1]+v.se,dp[v.fi][0]);
}
long long choose=inf,notchoose=0;
for (auto v:a[u]){
    //if (v.fi==par)continue;
    if (v.fi!=par){
        g[v.fi][0]=notchoose;
        g[v.fi][1]=choose;
    }
    choose=max(choose+max(dp[v.fi][0],dp[v.fi][1]+v.se),notchoose+dp[v.fi][0]+v.se);
    notchoose=notchoose+max(dp[v.fi][0],dp[v.fi][1]+v.se);
}
dp[u][1]=choose;
f[0]=0;
f[1]=inf;
f[2]=inf;
for (auto v:a[u]){
    f[2]=max(f[2]+max(dp[v.fi][0],dp[v.fi][1]+v.se),f[1]+dp[v.fi][0]+v.se);
    f[1]=max(f[1]+max(dp[v.fi][0],dp[v.fi][1]+v.se),f[0]+dp[v.fi][0]+v.se);
    f[0]+=max(dp[v.fi][0],dp[v.fi][1]+v.se);
}
ans=max(ans,f[2]);
choose=inf;
notchoose=0;
reverse(all(a[u]));
for (auto v:a[u]){
    //if (v.fi==par)continue;
    if (v.fi!=par){
        g[v.fi][1]+=notchoose;
        g[v.fi][0]+=choose;
    }
    choose=max(choose+max(dp[v.fi][0],dp[v.fi][1]+v.se),notchoose+dp[v.fi][0]+v.se);
    notchoose=notchoose+max(dp[v.fi][0],dp[v.fi][1]+v.se);
}
reverse(all(a[u]));
for (auto v:a[u]){
    if (v.fi==par)continue;
    long long c1=dp[u][0],c2=dp[u][1];
    dp[u][0]-=max(dp[v.fi][0],dp[v.fi][1]+v.se);
    dp[u][1]=max(g[v.fi][0],g[v.fi][1]);
    reroot(v.fi,u);
    dp[u][0]=c1;
    dp[u][1]=c2;
}
dp[u][0]=cop[u][0];
dp[u][1]=cop[u][1];
}
signed main(){
    srand(time(0));
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    //freopen(".INP","r",stdin);
    //freopen(".OUT","w",stdout);
    int n;
    cin>>n;
    for1(i,1,n-1){
    int u,v,w;
    cin>>u>>v>>w;
    a[u].pb({v,w});
    a[v].pb({u,w});
    }
    dfs1(1,0);
    ans=dp[1][0];
    reroot(1,0);
    cout<<ans;

}

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 3 ms 4948 KB Output is correct
4 Correct 3 ms 4948 KB Output is correct
5 Correct 3 ms 4948 KB Output is correct
6 Correct 3 ms 4948 KB Output is correct
7 Correct 4 ms 4948 KB Output is correct
8 Correct 3 ms 4948 KB Output is correct
9 Correct 3 ms 4948 KB Output is correct
10 Correct 3 ms 5028 KB Output is correct
11 Correct 3 ms 5004 KB Output is correct
12 Correct 4 ms 5028 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 3 ms 4948 KB Output is correct
4 Correct 3 ms 4948 KB Output is correct
5 Correct 3 ms 4948 KB Output is correct
6 Correct 3 ms 4948 KB Output is correct
7 Correct 4 ms 4948 KB Output is correct
8 Correct 3 ms 4948 KB Output is correct
9 Correct 3 ms 4948 KB Output is correct
10 Correct 3 ms 5028 KB Output is correct
11 Correct 3 ms 5004 KB Output is correct
12 Correct 4 ms 5028 KB Output is correct
13 Correct 3 ms 5028 KB Output is correct
14 Correct 3 ms 5024 KB Output is correct
15 Correct 3 ms 4948 KB Output is correct
16 Correct 4 ms 4948 KB Output is correct
17 Correct 3 ms 4948 KB Output is correct
18 Correct 3 ms 4948 KB Output is correct
19 Correct 3 ms 5076 KB Output is correct
20 Correct 3 ms 5076 KB Output is correct
21 Correct 3 ms 4948 KB Output is correct
22 Correct 4 ms 5032 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 3 ms 4948 KB Output is correct
4 Correct 3 ms 4948 KB Output is correct
5 Correct 3 ms 4948 KB Output is correct
6 Correct 3 ms 4948 KB Output is correct
7 Correct 4 ms 4948 KB Output is correct
8 Correct 3 ms 4948 KB Output is correct
9 Correct 3 ms 4948 KB Output is correct
10 Correct 3 ms 5028 KB Output is correct
11 Correct 3 ms 5004 KB Output is correct
12 Correct 4 ms 5028 KB Output is correct
13 Correct 3 ms 5028 KB Output is correct
14 Correct 3 ms 5024 KB Output is correct
15 Correct 3 ms 4948 KB Output is correct
16 Correct 4 ms 4948 KB Output is correct
17 Correct 3 ms 4948 KB Output is correct
18 Correct 3 ms 4948 KB Output is correct
19 Correct 3 ms 5076 KB Output is correct
20 Correct 3 ms 5076 KB Output is correct
21 Correct 3 ms 4948 KB Output is correct
22 Correct 4 ms 5032 KB Output is correct
23 Correct 7 ms 5460 KB Output is correct
24 Correct 6 ms 5460 KB Output is correct
25 Correct 7 ms 5460 KB Output is correct
26 Correct 7 ms 6064 KB Output is correct
27 Correct 8 ms 5972 KB Output is correct
28 Correct 6 ms 6100 KB Output is correct
29 Correct 7 ms 6100 KB Output is correct
30 Correct 7 ms 6100 KB Output is correct
31 Correct 8 ms 6356 KB Output is correct

Subtask #4
43.0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 3 ms 4948 KB Output is correct
4 Correct 3 ms 4948 KB Output is correct
5 Correct 3 ms 4948 KB Output is correct
6 Correct 3 ms 4948 KB Output is correct
7 Correct 4 ms 4948 KB Output is correct
8 Correct 3 ms 4948 KB Output is correct
9 Correct 3 ms 4948 KB Output is correct
10 Correct 3 ms 5028 KB Output is correct
11 Correct 3 ms 5004 KB Output is correct
12 Correct 4 ms 5028 KB Output is correct
13 Correct 3 ms 5028 KB Output is correct
14 Correct 3 ms 5024 KB Output is correct
15 Correct 3 ms 4948 KB Output is correct
16 Correct 4 ms 4948 KB Output is correct
17 Correct 3 ms 4948 KB Output is correct
18 Correct 3 ms 4948 KB Output is correct
19 Correct 3 ms 5076 KB Output is correct
20 Correct 3 ms 5076 KB Output is correct
21 Correct 3 ms 4948 KB Output is correct
22 Correct 4 ms 5032 KB Output is correct
23 Correct 7 ms 5460 KB Output is correct
24 Correct 6 ms 5460 KB Output is correct
25 Correct 7 ms 5460 KB Output is correct
26 Correct 7 ms 6064 KB Output is correct
27 Correct 8 ms 5972 KB Output is correct
28 Correct 6 ms 6100 KB Output is correct
29 Correct 7 ms 6100 KB Output is correct
30 Correct 7 ms 6100 KB Output is correct
31 Correct 8 ms 6356 KB Output is correct
32 Correct 37 ms 10192 KB Output is correct
33 Correct 39 ms 10152 KB Output is correct
34 Correct 41 ms 10132 KB Output is correct
35 Correct 220 ms 26180 KB Output is correct
36 Correct 231 ms 26216 KB Output is correct
37 Correct 199 ms 26172 KB Output is correct
38 Correct 144 ms 26540 KB Output is correct
39 Correct 158 ms 26516 KB Output is correct
40 Correct 157 ms 26548 KB Output is correct
41 Correct 201 ms 30100 KB Output is correct