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Submission #1002079

# Submission time Handle Problem Language Result Execution time Memory
1002079 2024-06-19T09:44:59 Z Tob Beads and wires (APIO14_beads) C++14
100 / 100
 119 ms 32444 KB 
#include <bits/stdc++.h>
 
#define ll long long
#define F first
#define S second
#define all(x) x.begin(), x.end()
#define pb push_back
#define FIO ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0)
 
using namespace std;
 
typedef pair <int, int> pii;
 
const int N = 2e5 + 7, inf = 2e9;
 
int n;
int dp[N][4];
vector <pii> adj[N];
 
void Upd(int& mx, int& mx2, int x) {
	if (x >= mx) {mx2 = mx; mx = x;}
	else if (x > mx2) mx2 = x;
}
 
void dfs(int x, int p = 0) {
	int siz = adj[x].size(), sum = 0, sum2 = 0, mxa = 0, mx = -inf, mx2 = -inf;
	vector <int> v, pre(siz+2, -inf), suf(siz+2, -inf);
	for (int i = 0; i < siz; i++) {
		pre[i+1] = pre[i];
		auto it = adj[x][i];
		if (it.F == p) continue;
		dfs(it.F, x);
		int X = max(dp[it.F][2], dp[it.F][3] + it.S);
		int Y = max(dp[it.F][0], dp[it.F][1] + it.S);
		int Z = dp[it.F][2] + it.S - X;
//		cout << it.F << " " << Z << "\n";
		pre[i+1] = max(pre[i+1], Z);
		suf[i+1] = Z;
		sum += X;
		sum2 += Y;
		mx = max(mx, dp[it.F][0] + it.S - X);
		mx2 = max(mx2, dp[it.F][2] + it.S - X);
		mxa = max(mxa, Y - X);
		v.pb(dp[it.F][2] + it.S - X);
	}
	int mx3 = 0;
	for (int i = siz-1; i >= 0; i--) {
		auto it = adj[x][i];
		suf[i+1] = max(suf[i+1], suf[i+2]);
		if (it.F == p) continue;
		int X = max(dp[it.F][2], dp[it.F][3] + it.S);
		mx3 = max(mx3, dp[it.F][0] - X + it.S + max(pre[i], suf[i+2]));
//		cout << i << " " << it.F << " " << pre[i] << " " << suf[i+2] << "\n";
	}
//	cout << "\n";
	
	dp[x][0] = sum + mxa;
	if (v.size() > 1) dp[x][0] = max(dp[x][0], sum + mx3);
	dp[x][1] = sum + mx;
	dp[x][2] = sum;
	dp[x][3] = sum + mx2;
	if (v.empty()) dp[x][1] = dp[x][3] = -inf;
	
//	cout << sum << " " << mxa << "\n";
//	cout << x << " -> " << dp[x][0] << " " << dp[x][1] << " " << dp[x][2] << " " << dp[x][3] << "\n";
}
 
int main () {
	FIO;
	cin >> n;
	
	for (int i = 1; i < n; i++) {
		int x, y, w; cin >> x >> y >> w;
		adj[x].pb({y, w});
		adj[y].pb({x, w});
	}
	
	dfs(1);
	
	cout << dp[1][0];
 
	return 0;
}

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4952 KB Output is correct
2 Correct 2 ms 4956 KB Output is correct
3 Correct 2 ms 4956 KB Output is correct
4 Correct 2 ms 4956 KB Output is correct
5 Correct 2 ms 4952 KB Output is correct
6 Correct 2 ms 4956 KB Output is correct
7 Correct 3 ms 4952 KB Output is correct
8 Correct 2 ms 4952 KB Output is correct
9 Correct 2 ms 4952 KB Output is correct
10 Correct 2 ms 4956 KB Output is correct
11 Correct 2 ms 4956 KB Output is correct
12 Correct 2 ms 4952 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4952 KB Output is correct
2 Correct 2 ms 4956 KB Output is correct
3 Correct 2 ms 4956 KB Output is correct
4 Correct 2 ms 4956 KB Output is correct
5 Correct 2 ms 4952 KB Output is correct
6 Correct 2 ms 4956 KB Output is correct
7 Correct 3 ms 4952 KB Output is correct
8 Correct 2 ms 4952 KB Output is correct
9 Correct 2 ms 4952 KB Output is correct
10 Correct 2 ms 4956 KB Output is correct
11 Correct 2 ms 4956 KB Output is correct
12 Correct 2 ms 4952 KB Output is correct
13 Correct 2 ms 4956 KB Output is correct
14 Correct 2 ms 4956 KB Output is correct
15 Correct 2 ms 4956 KB Output is correct
16 Correct 2 ms 4956 KB Output is correct
17 Correct 2 ms 4956 KB Output is correct
18 Correct 2 ms 4956 KB Output is correct
19 Correct 2 ms 5044 KB Output is correct
20 Correct 2 ms 4956 KB Output is correct
21 Correct 2 ms 4952 KB Output is correct
22 Correct 2 ms 5156 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4952 KB Output is correct
2 Correct 2 ms 4956 KB Output is correct
3 Correct 2 ms 4956 KB Output is correct
4 Correct 2 ms 4956 KB Output is correct
5 Correct 2 ms 4952 KB Output is correct
6 Correct 2 ms 4956 KB Output is correct
7 Correct 3 ms 4952 KB Output is correct
8 Correct 2 ms 4952 KB Output is correct
9 Correct 2 ms 4952 KB Output is correct
10 Correct 2 ms 4956 KB Output is correct
11 Correct 2 ms 4956 KB Output is correct
12 Correct 2 ms 4952 KB Output is correct
13 Correct 2 ms 4956 KB Output is correct
14 Correct 2 ms 4956 KB Output is correct
15 Correct 2 ms 4956 KB Output is correct
16 Correct 2 ms 4956 KB Output is correct
17 Correct 2 ms 4956 KB Output is correct
18 Correct 2 ms 4956 KB Output is correct
19 Correct 2 ms 5044 KB Output is correct
20 Correct 2 ms 4956 KB Output is correct
21 Correct 2 ms 4952 KB Output is correct
22 Correct 2 ms 5156 KB Output is correct
23 Correct 4 ms 5468 KB Output is correct
24 Correct 3 ms 5468 KB Output is correct
25 Correct 4 ms 5468 KB Output is correct
26 Correct 5 ms 5724 KB Output is correct
27 Correct 5 ms 5724 KB Output is correct
28 Correct 5 ms 5980 KB Output is correct
29 Correct 5 ms 5724 KB Output is correct
30 Correct 5 ms 5724 KB Output is correct
31 Correct 6 ms 6872 KB Output is correct

Subtask #4
43.0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4952 KB Output is correct
2 Correct 2 ms 4956 KB Output is correct
3 Correct 2 ms 4956 KB Output is correct
4 Correct 2 ms 4956 KB Output is correct
5 Correct 2 ms 4952 KB Output is correct
6 Correct 2 ms 4956 KB Output is correct
7 Correct 3 ms 4952 KB Output is correct
8 Correct 2 ms 4952 KB Output is correct
9 Correct 2 ms 4952 KB Output is correct
10 Correct 2 ms 4956 KB Output is correct
11 Correct 2 ms 4956 KB Output is correct
12 Correct 2 ms 4952 KB Output is correct
13 Correct 2 ms 4956 KB Output is correct
14 Correct 2 ms 4956 KB Output is correct
15 Correct 2 ms 4956 KB Output is correct
16 Correct 2 ms 4956 KB Output is correct
17 Correct 2 ms 4956 KB Output is correct
18 Correct 2 ms 4956 KB Output is correct
19 Correct 2 ms 5044 KB Output is correct
20 Correct 2 ms 4956 KB Output is correct
21 Correct 2 ms 4952 KB Output is correct
22 Correct 2 ms 5156 KB Output is correct
23 Correct 4 ms 5468 KB Output is correct
24 Correct 3 ms 5468 KB Output is correct
25 Correct 4 ms 5468 KB Output is correct
26 Correct 5 ms 5724 KB Output is correct
27 Correct 5 ms 5724 KB Output is correct
28 Correct 5 ms 5980 KB Output is correct
29 Correct 5 ms 5724 KB Output is correct
30 Correct 5 ms 5724 KB Output is correct
31 Correct 6 ms 6872 KB Output is correct
32 Correct 26 ms 8540 KB Output is correct
33 Correct 25 ms 8540 KB Output is correct
34 Correct 20 ms 8540 KB Output is correct
35 Correct 79 ms 19128 KB Output is correct
36 Correct 92 ms 19024 KB Output is correct
37 Correct 79 ms 19096 KB Output is correct
38 Correct 63 ms 22724 KB Output is correct
39 Correct 65 ms 21944 KB Output is correct
40 Correct 63 ms 21688 KB Output is correct
41 Correct 119 ms 32444 KB Output is correct