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Submission #345427

# Submission time Handle Problem Language Result Execution time Memory
345427 2021-01-07T09:39:31 Z alireza_kaviani Beads and wires (APIO14_beads) C++17
100 / 100
 260 ms 23976 KB 
#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>

using namespace std;
using namespace __gnu_pbds;

template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;

typedef long long ll;
typedef long double ld;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;

#define all(x)                      (x).begin(),(x).end()
#define Sort(x)                     sort(all((x)))
#define X                           first
#define Y                           second
#define sep                         ' '
#define endl                        '\n'
#define SZ(x)                       ll(x.size())

ll poww(ll a, ll b, ll md) {
    return (!b ? 1 : (b & 1 ? a * poww(a * a % md, b / 2, md) % md : poww(a * a % md, b / 2, md) % md));
}

const ll MAXN = 2e5 + 10;
const ll LOG = 22;
const ll INF = 8e18;
const ll MOD = 2e9 + 7; // 998244353; // 1e9 + 9;

int n , ans , dpDown[MAXN][2] , dpUp[MAXN][2] , W[MAXN] , res[MAXN];
vector<pii> adj[MAXN];

void DFSDown(int v , int p = -1){
	dpDown[v][0] = dpDown[v][1] = 0;
	int mx = -MOD;
	for(pii i : adj[v]){
		int u = i.X , w = i.Y;
		if(u == p)	continue;
		DFSDown(u , v);
		dpDown[v][0] += max(dpDown[u][0] , dpDown[u][1] + w);
		dpDown[v][1] += max(dpDown[u][0] , dpDown[u][1] + w);
		mx = max(mx , dpDown[u][0] + w - max(dpDown[u][0] , dpDown[u][1] + w));
	}
	dpDown[v][1] += mx;
}

void DFSUp(int v , int p = -1 , int w = -MOD){
	W[v] = w;
	int sum = max(dpUp[v][0] , dpUp[v][1] + w) , mx = dpUp[v][0] + w - max(dpUp[v][0] , dpUp[v][1] + w);
	for(pii i : adj[v]){
		int u = i.X , w = i.Y;
		if(u == p)	continue;
		sum += max(dpDown[u][0] , dpDown[u][1] + w);
		dpUp[u][1] = mx;
		mx = max(mx , dpDown[u][0] + w - max(dpDown[u][0] , dpDown[u][1] + w));
	}
	mx = -MOD;
	reverse(all(adj[v]));
	for(pii i : adj[v]){
		int u = i.X , w = i.Y;
		if(u == p)	continue;
		dpUp[u][1] = max(dpUp[u][1] , mx);
		dpUp[u][0] = sum - max(dpDown[u][0] , dpDown[u][1] + w);
		dpUp[u][1] += dpUp[u][0];
		mx = max(mx , dpDown[u][0] + w - max(dpDown[u][0] , dpDown[u][1] + w));
		DFSUp(u , v , w);
	}
	//cout << v << sep << dpDown[v][0] << sep << dpDown[v][1] << sep << dpUp[v][0] << sep << dpUp[v][1] << endl;
}

int main() {
    ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);

	cin >> n;
	//if(n > 10000)	return 0;
	for(int i = 1 ; i < n ; i++){
		int v , u , w;
		cin >> v >> u >> w;
		adj[v].push_back({u , w});
		adj[u].push_back({v , w});
	}
	DFSDown(1);
	DFSUp(1);
	for(int i = 1 ; i <= n ; i++){
		ans = max(ans , dpDown[i][0] + max(dpUp[i][0] , dpUp[i][1] + W[i]));
		res[i] = dpDown[i][0] + max(dpUp[i][0] , dpUp[i][1] + W[i]);
	}
	/*for(int i = 1 ; i <= n ; i++){
		DFSDown(i);
		cout << i << sep << res[i] << sep << dpDown[i][0] << sep << dpDown[i][1] << sep << dpUp[i][0] << sep << dpUp[i][1] << endl;
	}*/
	cout << ans << endl;

    return 0;
}
/*

*/

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 5100 KB Output is correct
2 Correct 4 ms 5100 KB Output is correct
3 Correct 5 ms 5100 KB Output is correct
4 Correct 5 ms 5100 KB Output is correct
5 Correct 4 ms 5100 KB Output is correct
6 Correct 4 ms 5100 KB Output is correct
7 Correct 4 ms 5100 KB Output is correct
8 Correct 4 ms 5100 KB Output is correct
9 Correct 4 ms 5100 KB Output is correct
10 Correct 4 ms 5100 KB Output is correct
11 Correct 5 ms 5100 KB Output is correct
12 Correct 4 ms 5100 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 5100 KB Output is correct
2 Correct 4 ms 5100 KB Output is correct
3 Correct 5 ms 5100 KB Output is correct
4 Correct 5 ms 5100 KB Output is correct
5 Correct 4 ms 5100 KB Output is correct
6 Correct 4 ms 5100 KB Output is correct
7 Correct 4 ms 5100 KB Output is correct
8 Correct 4 ms 5100 KB Output is correct
9 Correct 4 ms 5100 KB Output is correct
10 Correct 4 ms 5100 KB Output is correct
11 Correct 5 ms 5100 KB Output is correct
12 Correct 4 ms 5100 KB Output is correct
13 Correct 4 ms 5100 KB Output is correct
14 Correct 4 ms 5100 KB Output is correct
15 Correct 4 ms 5100 KB Output is correct
16 Correct 4 ms 5100 KB Output is correct
17 Correct 5 ms 5100 KB Output is correct
18 Correct 4 ms 5100 KB Output is correct
19 Correct 4 ms 5100 KB Output is correct
20 Correct 4 ms 5100 KB Output is correct
21 Correct 4 ms 5100 KB Output is correct
22 Correct 4 ms 5100 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 5100 KB Output is correct
2 Correct 4 ms 5100 KB Output is correct
3 Correct 5 ms 5100 KB Output is correct
4 Correct 5 ms 5100 KB Output is correct
5 Correct 4 ms 5100 KB Output is correct
6 Correct 4 ms 5100 KB Output is correct
7 Correct 4 ms 5100 KB Output is correct
8 Correct 4 ms 5100 KB Output is correct
9 Correct 4 ms 5100 KB Output is correct
10 Correct 4 ms 5100 KB Output is correct
11 Correct 5 ms 5100 KB Output is correct
12 Correct 4 ms 5100 KB Output is correct
13 Correct 4 ms 5100 KB Output is correct
14 Correct 4 ms 5100 KB Output is correct
15 Correct 4 ms 5100 KB Output is correct
16 Correct 4 ms 5100 KB Output is correct
17 Correct 5 ms 5100 KB Output is correct
18 Correct 4 ms 5100 KB Output is correct
19 Correct 4 ms 5100 KB Output is correct
20 Correct 4 ms 5100 KB Output is correct
21 Correct 4 ms 5100 KB Output is correct
22 Correct 4 ms 5100 KB Output is correct
23 Correct 6 ms 5484 KB Output is correct
24 Correct 10 ms 5484 KB Output is correct
25 Correct 6 ms 5484 KB Output is correct
26 Correct 9 ms 5868 KB Output is correct
27 Correct 9 ms 5868 KB Output is correct
28 Correct 8 ms 5868 KB Output is correct
29 Correct 8 ms 5868 KB Output is correct
30 Correct 8 ms 5868 KB Output is correct
31 Correct 12 ms 6124 KB Output is correct

Subtask #4
43.0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 5100 KB Output is correct
2 Correct 4 ms 5100 KB Output is correct
3 Correct 5 ms 5100 KB Output is correct
4 Correct 5 ms 5100 KB Output is correct
5 Correct 4 ms 5100 KB Output is correct
6 Correct 4 ms 5100 KB Output is correct
7 Correct 4 ms 5100 KB Output is correct
8 Correct 4 ms 5100 KB Output is correct
9 Correct 4 ms 5100 KB Output is correct
10 Correct 4 ms 5100 KB Output is correct
11 Correct 5 ms 5100 KB Output is correct
12 Correct 4 ms 5100 KB Output is correct
13 Correct 4 ms 5100 KB Output is correct
14 Correct 4 ms 5100 KB Output is correct
15 Correct 4 ms 5100 KB Output is correct
16 Correct 4 ms 5100 KB Output is correct
17 Correct 5 ms 5100 KB Output is correct
18 Correct 4 ms 5100 KB Output is correct
19 Correct 4 ms 5100 KB Output is correct
20 Correct 4 ms 5100 KB Output is correct
21 Correct 4 ms 5100 KB Output is correct
22 Correct 4 ms 5100 KB Output is correct
23 Correct 6 ms 5484 KB Output is correct
24 Correct 10 ms 5484 KB Output is correct
25 Correct 6 ms 5484 KB Output is correct
26 Correct 9 ms 5868 KB Output is correct
27 Correct 9 ms 5868 KB Output is correct
28 Correct 8 ms 5868 KB Output is correct
29 Correct 8 ms 5868 KB Output is correct
30 Correct 8 ms 5868 KB Output is correct
31 Correct 12 ms 6124 KB Output is correct
32 Correct 37 ms 8812 KB Output is correct
33 Correct 41 ms 8812 KB Output is correct
34 Correct 37 ms 8812 KB Output is correct
35 Correct 260 ms 20700 KB Output is correct
36 Correct 248 ms 20740 KB Output is correct
37 Correct 258 ms 20816 KB Output is correct
38 Correct 148 ms 21084 KB Output is correct
39 Correct 145 ms 21204 KB Output is correct
40 Correct 150 ms 20964 KB Output is correct
41 Correct 218 ms 23976 KB Output is correct