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Submission #312764

# Submission time Handle Problem Language Result Execution time Memory
312764 2020-10-14T10:22:39 Z hohohaha Beads and wires (APIO14_beads) C++14
100 / 100
 278 ms 29796 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
}
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]; 
			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 5 ms 4992 KB Output is correct
7 Correct 4 ms 4992 KB Output is correct
8 Correct 5 ms 5120 KB Output is correct
9 Correct 4 ms 4992 KB Output is correct
10 Correct 5 ms 4992 KB Output is correct
11 Correct 4 ms 5120 KB Output is correct
12 Correct 4 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 5 ms 4992 KB Output is correct
7 Correct 4 ms 4992 KB Output is correct
8 Correct 5 ms 5120 KB Output is correct
9 Correct 4 ms 4992 KB Output is correct
10 Correct 5 ms 4992 KB Output is correct
11 Correct 4 ms 5120 KB Output is correct
12 Correct 4 ms 4992 KB Output is correct
13 Correct 3 ms 5120 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 5120 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 5120 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 5 ms 4992 KB Output is correct
7 Correct 4 ms 4992 KB Output is correct
8 Correct 5 ms 5120 KB Output is correct
9 Correct 4 ms 4992 KB Output is correct
10 Correct 5 ms 4992 KB Output is correct
11 Correct 4 ms 5120 KB Output is correct
12 Correct 4 ms 4992 KB Output is correct
13 Correct 3 ms 5120 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 5120 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 5120 KB Output is correct
22 Correct 4 ms 5120 KB Output is correct
23 Correct 6 ms 5632 KB Output is correct
24 Correct 6 ms 5632 KB Output is correct
25 Correct 7 ms 5632 KB Output is correct
26 Correct 9 ms 6144 KB Output is correct
27 Correct 10 ms 6144 KB Output is correct
28 Correct 9 ms 6140 KB Output is correct
29 Correct 9 ms 6016 KB Output is correct
30 Correct 9 ms 6144 KB Output is correct
31 Correct 9 ms 6656 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 5 ms 4992 KB Output is correct
7 Correct 4 ms 4992 KB Output is correct
8 Correct 5 ms 5120 KB Output is correct
9 Correct 4 ms 4992 KB Output is correct
10 Correct 5 ms 4992 KB Output is correct
11 Correct 4 ms 5120 KB Output is correct
12 Correct 4 ms 4992 KB Output is correct
13 Correct 3 ms 5120 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 5120 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 5120 KB Output is correct
22 Correct 4 ms 5120 KB Output is correct
23 Correct 6 ms 5632 KB Output is correct
24 Correct 6 ms 5632 KB Output is correct
25 Correct 7 ms 5632 KB Output is correct
26 Correct 9 ms 6144 KB Output is correct
27 Correct 10 ms 6144 KB Output is correct
28 Correct 9 ms 6140 KB Output is correct
29 Correct 9 ms 6016 KB Output is correct
30 Correct 9 ms 6144 KB Output is correct
31 Correct 9 ms 6656 KB Output is correct
32 Correct 42 ms 10488 KB Output is correct
33 Correct 44 ms 10488 KB Output is correct
34 Correct 47 ms 10492 KB Output is correct
35 Correct 268 ms 25208 KB Output is correct
36 Correct 278 ms 25212 KB Output is correct
37 Correct 259 ms 25164 KB Output is correct
38 Correct 161 ms 24416 KB Output is correct
39 Correct 160 ms 21192 KB Output is correct
40 Correct 175 ms 24532 KB Output is correct
41 Correct 234 ms 29796 KB Output is correct