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Submission #312762

# Submission time Handle Problem Language Result Execution time Memory
312762 2020-10-14T10:21:45 Z hohohaha Beads and wires (APIO14_beads) C++14
100 / 100
 552 ms 32868 KB 
#include<bits/stdc++.h>

using namespace std;

#define int long long

#define ii pair<int, int>
#define iii pair<ii, int>

#define mp make_pair
#define eb emplace_back

#define vi vector<int>
#define vii vector<ii>
#define viii vector<iii>

#define fi first
#define se second
#define xx fi.fi
#define yy fi.se
#define zz se
int n, ans, mxw[200005][2], dp[200005][2], pw[200005], p[200005];
vii G[200005];
void dfs(int u)
{
	int mxr = LLONG_MIN/100LL;
	for(ii e: G[u])
	{
		int v = e.fi, w = e.se;
		if(v!=p[u])
		{
			p[v] = u;
			pw[v] = w;
			dfs(v);
			dp[u][0]+=dp[v][1];
			int replace = dp[v][0] - dp[v][1] + w;
			mxr = max(mxr, replace);
			int temp = mxw[u][0], mx0 = mxw[u][0], mx1 = mxw[u][1];
			if(!mx0 or replace>dp[mx0][0] - dp[mx0][1] + pw[mx0])
			{
				mxw[u][1] = mxw[u][0];
				mxw[u][0] = v;
			}
			else if(!mx1 or replace> dp[mx1][0] - dp[mx1][1] + pw[mx1])
			{
				mxw[u][1] = v;
			}
		}
	}
	dp[u][1] = max(dp[u][0], (u==1? LLONG_MIN/100LL: pw[u] + mxr + dp[u][0])); //toi quen th u = 1 ditme
//	cout<<u<<" "<<dp[u][0]<<" "<<dp[u][1]<<endl;
}
void euler(int u)
{
	ans = max(ans, dp[u][0]);
	for(ii e: G[u])
	{
		int v = e.fi, w = e.se;
		if(v!=p[u])
		{
			// reroot
			int tu0 = dp[u][0], tu1 = dp[u][1], tv0 = dp[v][0], tv1 = dp[v][1];
			int mxid = mxw[u][0]==v? mxw[u][1]: mxw[u][0];
			int mx = max((!mxid? LLONG_MIN/100ll: dp[mxid][0] - dp[mxid][1] + pw[mxid]), (!p[u]? LLONG_MIN/100LL: dp[p[u]][0] - dp[p[u]][1] + pw[u])); // toi quen truong hop mxid = 0 ditme
			dp[u][0] = dp[u][0] - dp[v][1];
			dp[u][1] = max(dp[u][0], dp[u][0] + mx + w);
			dp[v][0] = dp[v][1] = dp[v][0]+dp[u][1]; 
//			cout<<mx<<endl;
//			cout<<u<<" "<<v<<" "<<dp[u][0]<<" "<<dp[u][1]<<" "<<dp[v][1]<<endl;
			euler(v);
			//rollback
			dp[u][0] = tu0, dp[u][1] = tu1, dp[v][0] = tv0, dp[v][1] = tv1;
		}
	}
}
signed main()
{
// 	freopen(".inp", "r", stdin);
// 	freopen(".out", "w", stdout);
// 	ios_base::sync_with_stdio(false);
//    cin.tie(NULL);
//    cout.tie(NULL);
    cin>>n;
    for(int i=1; i<=n-1; i++)
    {
    	int u, v, w;
    	cin>>u>>v>>w;
    	G[u].eb(v, w);
    	G[v].eb(u, w);
	}
	dfs(1);
	euler(1);
	cout<<ans;
}

Compilation message

beads.cpp: In function 'void dfs(long long int)':
beads.cpp:38:8: warning: unused variable 'temp' [-Wunused-variable]
   38 |    int temp = mxw[u][0], mx0 = mxw[u][0], mx1 = mxw[u][1];
      |        ^~~~

Subtask #1
13.0 / 13.0

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

Subtask #2
15.0 / 15.0

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

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 4992 KB Output is correct
2 Correct 4 ms 4992 KB Output is correct
3 Correct 4 ms 4992 KB Output is correct
4 Correct 4 ms 4992 KB Output is correct
5 Correct 4 ms 4992 KB Output is correct
6 Correct 4 ms 4992 KB Output is correct
7 Correct 4 ms 4992 KB Output is correct
8 Correct 4 ms 4992 KB Output is correct
9 Correct 5 ms 4992 KB Output is correct
10 Correct 4 ms 4992 KB Output is correct
11 Correct 4 ms 4992 KB Output is correct
12 Correct 5 ms 4992 KB Output is correct
13 Correct 4 ms 4992 KB Output is correct
14 Correct 4 ms 4992 KB Output is correct
15 Correct 4 ms 4992 KB Output is correct
16 Correct 4 ms 5120 KB Output is correct
17 Correct 4 ms 5120 KB Output is correct
18 Correct 4 ms 4992 KB Output is correct
19 Correct 4 ms 5120 KB Output is correct
20 Correct 4 ms 5120 KB Output is correct
21 Correct 4 ms 4992 KB Output is correct
22 Correct 4 ms 5120 KB Output is correct
23 Correct 12 ms 5632 KB Output is correct
24 Correct 12 ms 5632 KB Output is correct
25 Correct 12 ms 5632 KB Output is correct
26 Correct 24 ms 6144 KB Output is correct
27 Correct 22 ms 6144 KB Output is correct
28 Correct 22 ms 6132 KB Output is correct
29 Correct 20 ms 6016 KB Output is correct
30 Correct 20 ms 6144 KB Output is correct
31 Correct 23 ms 6528 KB Output is correct

Subtask #4
43.0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 4992 KB Output is correct
2 Correct 4 ms 4992 KB Output is correct
3 Correct 4 ms 4992 KB Output is correct
4 Correct 4 ms 4992 KB Output is correct
5 Correct 4 ms 4992 KB Output is correct
6 Correct 4 ms 4992 KB Output is correct
7 Correct 4 ms 4992 KB Output is correct
8 Correct 4 ms 4992 KB Output is correct
9 Correct 5 ms 4992 KB Output is correct
10 Correct 4 ms 4992 KB Output is correct
11 Correct 4 ms 4992 KB Output is correct
12 Correct 5 ms 4992 KB Output is correct
13 Correct 4 ms 4992 KB Output is correct
14 Correct 4 ms 4992 KB Output is correct
15 Correct 4 ms 4992 KB Output is correct
16 Correct 4 ms 5120 KB Output is correct
17 Correct 4 ms 5120 KB Output is correct
18 Correct 4 ms 4992 KB Output is correct
19 Correct 4 ms 5120 KB Output is correct
20 Correct 4 ms 5120 KB Output is correct
21 Correct 4 ms 4992 KB Output is correct
22 Correct 4 ms 5120 KB Output is correct
23 Correct 12 ms 5632 KB Output is correct
24 Correct 12 ms 5632 KB Output is correct
25 Correct 12 ms 5632 KB Output is correct
26 Correct 24 ms 6144 KB Output is correct
27 Correct 22 ms 6144 KB Output is correct
28 Correct 22 ms 6132 KB Output is correct
29 Correct 20 ms 6016 KB Output is correct
30 Correct 20 ms 6144 KB Output is correct
31 Correct 23 ms 6528 KB Output is correct
32 Correct 117 ms 10872 KB Output is correct
33 Correct 108 ms 10744 KB Output is correct
34 Correct 120 ms 10712 KB Output is correct
35 Correct 545 ms 28152 KB Output is correct
36 Correct 545 ms 28152 KB Output is correct
37 Correct 552 ms 28280 KB Output is correct
38 Correct 452 ms 27752 KB Output is correct
39 Correct 432 ms 24260 KB Output is correct
40 Correct 456 ms 27576 KB Output is correct
41 Correct 515 ms 32868 KB Output is correct