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Submission #48364

# Submission time Handle Problem Language Result Execution time Memory
48364 2018-05-12T02:51:25 Z tmwilliamlin168 Beads and wires (APIO14_beads) C++11
100 / 100
 232 ms 20308 KB 
#include <bits/stdc++.h>
using namespace std;

#define pii pair<int, int>
#define fi first
#define se second

const int mxN=2e5;
int n, dp[mxN][4];
vector<pii> adj[mxN];

void dfs1(int u, int p, int a) {
	int m1=0, m2=0, m3=0, mi1=-1, mi2, mi3=-1, mi4;
	for(pii e : adj[u]) {
		int v=e.fi;
		if(v==p)
			continue;
		dfs1(v, u, e.se);
		dp[u][0]+=dp[v][0];
		m1=max(dp[v][2]-dp[v][0]+a, m1);
		m2=max(dp[v][1]-dp[v][0], m2);
		m3=max(dp[v][3]-dp[v][0]+a, m3);
		if(mi1==-1||dp[v][2]-dp[v][0]>dp[mi1][2]-dp[mi1][0]) {
			mi2=mi1;
			mi1=v;
		} else if(mi2==-1||dp[v][2]-dp[v][0]>dp[mi2][2]-dp[mi2][0])
			mi2=v;
		if(mi3==-1||dp[v][3]-dp[v][0]>dp[mi3][3]-dp[mi3][0]) {
			mi4=mi3;
			mi3=v;
		} else if(mi4==-1||dp[v][3]-dp[v][0]>dp[mi4][3]-dp[mi4][0])
			mi4=v;
	}
	dp[u][2]=dp[u][0]+a;
	dp[u][1]=dp[u][0]+m2;
//	cout << mi1 << " " << mi2 << " " << mi3 << " " << mi4 << endl;
	if(mi1!=-1&&mi3!=-1)
		dp[u][1]=max(dp[u][0]+(mi1!=mi3?dp[mi1][2]-dp[mi1][0]+dp[mi3][3]-dp[mi3][0]:max(mi2==-1?0:dp[mi2][2]-dp[mi2][0]+dp[mi3][3]-dp[mi3][0], mi4==-1?0:dp[mi1][2]-dp[mi1][0]+dp[mi4][3]-dp[mi4][0])), dp[u][1]);
	dp[u][3]=dp[u][1]+a;
	dp[u][1]=max(dp[u][0]+m3, dp[u][1]);
	dp[u][0]+=m1;
//	cout << dp[u][0] << " " << dp[u][1] << " " << dp[u][2] << " " << dp[u][3] << " " << u << endl;
}

int main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	
	cin >> n;
	for(int i=0; i<n-1; ++i) {
		int u, v, c;
		cin >> u >> v >> c, --u, --v;
		adj[u].push_back({v, c});
		adj[v].push_back({u, c});
	}
	dfs1(0, -1, -2e9);
	cout << dp[0][1];
}

Compilation message

beads.cpp: In function 'void dfs1(int, int, int)':
beads.cpp:38:179: warning: 'mi4' may be used uninitialized in this function [-Wmaybe-uninitialized]
   dp[u][1]=max(dp[u][0]+(mi1!=mi3?dp[mi1][2]-dp[mi1][0]+dp[mi3][3]-dp[mi3][0]:max(mi2==-1?0:dp[mi2][2]-dp[mi2][0]+dp[mi3][3]-dp[mi3][0], mi4==-1?0:dp[mi1][2]-dp[mi1][0]+dp[mi4][3]-dp[mi4][0])), dp[u][1]);
                                                                                                                                                                          ~~~~~~~~~^
beads.cpp:38:102: warning: 'mi2' may be used uninitialized in this function [-Wmaybe-uninitialized]
   dp[u][1]=max(dp[u][0]+(mi1!=mi3?dp[mi1][2]-dp[mi1][0]+dp[mi3][3]-dp[mi3][0]:max(mi2==-1?0:dp[mi2][2]-dp[mi2][0]+dp[mi3][3]-dp[mi3][0], mi4==-1?0:dp[mi1][2]-dp[mi1][0]+dp[mi4][3]-dp[mi4][0])), dp[u][1]);
                                                                                             ~~~~~~~~~^

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 4992 KB Output is correct
2 Correct 5 ms 4992 KB Output is correct
3 Correct 6 ms 5120 KB Output is correct
4 Correct 6 ms 5120 KB Output is correct
5 Correct 6 ms 5120 KB Output is correct
6 Correct 6 ms 5120 KB Output is correct
7 Correct 5 ms 5120 KB Output is correct
8 Correct 7 ms 5120 KB Output is correct
9 Correct 5 ms 4992 KB Output is correct
10 Correct 6 ms 5120 KB Output is correct
11 Correct 7 ms 4992 KB Output is correct
12 Correct 5 ms 5036 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 4992 KB Output is correct
2 Correct 5 ms 4992 KB Output is correct
3 Correct 6 ms 5120 KB Output is correct
4 Correct 6 ms 5120 KB Output is correct
5 Correct 6 ms 5120 KB Output is correct
6 Correct 6 ms 5120 KB Output is correct
7 Correct 5 ms 5120 KB Output is correct
8 Correct 7 ms 5120 KB Output is correct
9 Correct 5 ms 4992 KB Output is correct
10 Correct 6 ms 5120 KB Output is correct
11 Correct 7 ms 4992 KB Output is correct
12 Correct 5 ms 5036 KB Output is correct
13 Correct 5 ms 4992 KB Output is correct
14 Correct 6 ms 4992 KB Output is correct
15 Correct 6 ms 4992 KB Output is correct
16 Correct 8 ms 4988 KB Output is correct
17 Correct 5 ms 4992 KB Output is correct
18 Correct 24 ms 4992 KB Output is correct
19 Correct 9 ms 4992 KB Output is correct
20 Correct 6 ms 4992 KB Output is correct
21 Correct 6 ms 4992 KB Output is correct
22 Correct 6 ms 4992 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 4992 KB Output is correct
2 Correct 5 ms 4992 KB Output is correct
3 Correct 6 ms 5120 KB Output is correct
4 Correct 6 ms 5120 KB Output is correct
5 Correct 6 ms 5120 KB Output is correct
6 Correct 6 ms 5120 KB Output is correct
7 Correct 5 ms 5120 KB Output is correct
8 Correct 7 ms 5120 KB Output is correct
9 Correct 5 ms 4992 KB Output is correct
10 Correct 6 ms 5120 KB Output is correct
11 Correct 7 ms 4992 KB Output is correct
12 Correct 5 ms 5036 KB Output is correct
13 Correct 5 ms 4992 KB Output is correct
14 Correct 6 ms 4992 KB Output is correct
15 Correct 6 ms 4992 KB Output is correct
16 Correct 8 ms 4988 KB Output is correct
17 Correct 5 ms 4992 KB Output is correct
18 Correct 24 ms 4992 KB Output is correct
19 Correct 9 ms 4992 KB Output is correct
20 Correct 6 ms 4992 KB Output is correct
21 Correct 6 ms 4992 KB Output is correct
22 Correct 6 ms 4992 KB Output is correct
23 Correct 9 ms 5376 KB Output is correct
24 Correct 9 ms 5248 KB Output is correct
25 Correct 8 ms 5376 KB Output is correct
26 Correct 10 ms 5504 KB Output is correct
27 Correct 10 ms 5504 KB Output is correct
28 Correct 10 ms 5632 KB Output is correct
29 Correct 10 ms 5632 KB Output is correct
30 Correct 11 ms 5644 KB Output is correct
31 Correct 11 ms 6016 KB Output is correct

Subtask #4
43.0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 4992 KB Output is correct
2 Correct 5 ms 4992 KB Output is correct
3 Correct 6 ms 5120 KB Output is correct
4 Correct 6 ms 5120 KB Output is correct
5 Correct 6 ms 5120 KB Output is correct
6 Correct 6 ms 5120 KB Output is correct
7 Correct 5 ms 5120 KB Output is correct
8 Correct 7 ms 5120 KB Output is correct
9 Correct 5 ms 4992 KB Output is correct
10 Correct 6 ms 5120 KB Output is correct
11 Correct 7 ms 4992 KB Output is correct
12 Correct 5 ms 5036 KB Output is correct
13 Correct 5 ms 4992 KB Output is correct
14 Correct 6 ms 4992 KB Output is correct
15 Correct 6 ms 4992 KB Output is correct
16 Correct 8 ms 4988 KB Output is correct
17 Correct 5 ms 4992 KB Output is correct
18 Correct 24 ms 4992 KB Output is correct
19 Correct 9 ms 4992 KB Output is correct
20 Correct 6 ms 4992 KB Output is correct
21 Correct 6 ms 4992 KB Output is correct
22 Correct 6 ms 4992 KB Output is correct
23 Correct 9 ms 5376 KB Output is correct
24 Correct 9 ms 5248 KB Output is correct
25 Correct 8 ms 5376 KB Output is correct
26 Correct 10 ms 5504 KB Output is correct
27 Correct 10 ms 5504 KB Output is correct
28 Correct 10 ms 5632 KB Output is correct
29 Correct 10 ms 5632 KB Output is correct
30 Correct 11 ms 5644 KB Output is correct
31 Correct 11 ms 6016 KB Output is correct
32 Correct 37 ms 7636 KB Output is correct
33 Correct 32 ms 7672 KB Output is correct
34 Correct 39 ms 7672 KB Output is correct
35 Correct 232 ms 15740 KB Output is correct
36 Correct 208 ms 15736 KB Output is correct
37 Correct 217 ms 15852 KB Output is correct
38 Correct 157 ms 16112 KB Output is correct
39 Correct 132 ms 16092 KB Output is correct
40 Correct 150 ms 15840 KB Output is correct
41 Correct 198 ms 20308 KB Output is correct