oj.uz

Submission #162291

# Submission time Handle Problem Language Result Execution time Memory
162291 2019-11-07T13:26:20 Z amoo_safar Beads and wires (APIO14_beads) C++14
100 / 100
 343 ms 40752 KB 
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>

#define pb push_back
#define F first
#define S second
#define all(x) x.begin(), x.end()
#define debug(x) cerr << #x << " : " << x << '\n'

using namespace std;
using namespace __gnu_pbds;

typedef long long ll;
typedef long double ld;
typedef string str;
typedef pair<ll, ll> pll;
typedef pair<pll, pll> node;
typedef tree<ll, null_type, less<ll>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;

const ll Mod = 1000000007LL;
const int Maxn = 2e5 + 10;
const int Maxk = 60;
const ll Inf = 2242545357980376863LL;
const ll Log = 30;

vector<pll> G[Maxn];

ll dp1[Maxn], dp2[Maxn];

ll DFS(ll u, ll p){
	ll adj;
	ll mx = -Inf;
	for(auto ed : G[u]){
		adj = ed.F;
		if(adj == p) continue;
		DFS(adj, u);
		dp1[u] += max(dp1[adj], dp2[adj] + ed.S);
		mx = max(mx, ed.S + dp1[adj] - max(dp1[adj], dp2[adj] + ed.S));
	}
	dp2[u] = dp1[u] + mx;
}

ll dpu1[Maxn], dpu2[Maxn];
ll pssm[Maxn], psmx[Maxn];
ll sfsm[Maxn], sfmx[Maxn];
ll ans = 0;
ll dfs(ll u, ll p, ll w){
	vector< pair<pll, pll> > S;
	ll adj;
	for(auto ed : G[u]){
		adj = ed.F;
		if(adj == p){
			S.pb({{dpu1[u], dpu2[u]}, {w, adj}});
		} else {
			S.pb({{dp1[adj], dp2[adj]}, {ed.S, adj}});
		}
	}
	ll N = S.size();
	
	pssm[0] = 0;
	for(int i = 1; i <= N; i++) pssm[i] = pssm[i - 1] + max(S[i - 1].F.F, S[i - 1].F.S + S[i - 1].S.F);
	psmx[0] = -Inf;
	for(int i = 1; i <= N; i++) psmx[i] = max(psmx[i - 1] , S[i - 1].F.F + S[i - 1].S.F - max(S[i - 1].F.F, S[i - 1].F.S + S[i - 1].S.F) );
	reverse(all(S));
	for(int i = 0; i <= N; i++) sfsm[i] = pssm[i];
	for(int i = 0; i <= N; i++) sfmx[i] = psmx[i];
	//swap(pssm, sfsm);
	//swap(psmx, sfmx);
	
	pssm[0] = 0;
	for(int i = 1; i <= N; i++) pssm[i] = pssm[i - 1] + max(S[i - 1].F.F, S[i - 1].F.S + S[i - 1].S.F);
	psmx[0] = -Inf;
	for(int i = 1; i <= N; i++) psmx[i] = max(psmx[i - 1] , S[i - 1].F.F + S[i - 1].S.F - max(S[i - 1].F.F, S[i - 1].F.S + S[i - 1].S.F) );
	//if(u == 3) cerr << 
	ans = max(pssm[N], ans);
	
	for(int i = 0; i < N; i++){
		adj = S[i].S.S;
		if(adj == p) continue;
		dpu1[adj] = pssm[i] + sfsm[N - 1 - i];
		dpu2[adj] = dpu1[adj] + max(psmx[i], sfmx[N - 1 - i]);
	}
	
	for(auto ed : G[u]){
		adj = ed.F;
		if(adj != p) dfs(adj, u, ed.S);
	}
}


int main(){
	ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	ll n;
	cin >> n;
	ll u, v, w;
	for(int i = 1; i < n; i++){
		cin >> u >> v >> w;
		G[u].pb({v, w});
		G[v].pb({u, w});
	}
	DFS(1, -1);
	dfs(1, -1, 0);
	cout << ans;
	return 0;
}
/*
5
1 2 10
1 3 40
1 4 15
1 5 20

*/

Compilation message

beads.cpp: In function 'll DFS(ll, ll)':
beads.cpp:41:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^
beads.cpp: In function 'll dfs(ll, ll, ll)':
beads.cpp:88:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 5116 KB Output is correct
2 Correct 6 ms 5112 KB Output is correct
3 Correct 6 ms 5116 KB Output is correct
4 Correct 7 ms 5112 KB Output is correct
5 Correct 6 ms 5112 KB Output is correct
6 Correct 6 ms 5112 KB Output is correct
7 Correct 6 ms 5112 KB Output is correct
8 Correct 6 ms 5084 KB Output is correct
9 Correct 6 ms 5112 KB Output is correct
10 Correct 6 ms 5112 KB Output is correct
11 Correct 6 ms 5112 KB Output is correct
12 Correct 6 ms 5112 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 5116 KB Output is correct
2 Correct 6 ms 5112 KB Output is correct
3 Correct 6 ms 5116 KB Output is correct
4 Correct 7 ms 5112 KB Output is correct
5 Correct 6 ms 5112 KB Output is correct
6 Correct 6 ms 5112 KB Output is correct
7 Correct 6 ms 5112 KB Output is correct
8 Correct 6 ms 5084 KB Output is correct
9 Correct 6 ms 5112 KB Output is correct
10 Correct 6 ms 5112 KB Output is correct
11 Correct 6 ms 5112 KB Output is correct
12 Correct 6 ms 5112 KB Output is correct
13 Correct 6 ms 5112 KB Output is correct
14 Correct 6 ms 5112 KB Output is correct
15 Correct 6 ms 5112 KB Output is correct
16 Correct 6 ms 5112 KB Output is correct
17 Correct 6 ms 5112 KB Output is correct
18 Correct 13 ms 5240 KB Output is correct
19 Correct 6 ms 5112 KB Output is correct
20 Correct 7 ms 5112 KB Output is correct
21 Correct 6 ms 5116 KB Output is correct
22 Correct 6 ms 5112 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 5116 KB Output is correct
2 Correct 6 ms 5112 KB Output is correct
3 Correct 6 ms 5116 KB Output is correct
4 Correct 7 ms 5112 KB Output is correct
5 Correct 6 ms 5112 KB Output is correct
6 Correct 6 ms 5112 KB Output is correct
7 Correct 6 ms 5112 KB Output is correct
8 Correct 6 ms 5084 KB Output is correct
9 Correct 6 ms 5112 KB Output is correct
10 Correct 6 ms 5112 KB Output is correct
11 Correct 6 ms 5112 KB Output is correct
12 Correct 6 ms 5112 KB Output is correct
13 Correct 6 ms 5112 KB Output is correct
14 Correct 6 ms 5112 KB Output is correct
15 Correct 6 ms 5112 KB Output is correct
16 Correct 6 ms 5112 KB Output is correct
17 Correct 6 ms 5112 KB Output is correct
18 Correct 13 ms 5240 KB Output is correct
19 Correct 6 ms 5112 KB Output is correct
20 Correct 7 ms 5112 KB Output is correct
21 Correct 6 ms 5116 KB Output is correct
22 Correct 6 ms 5112 KB Output is correct
23 Correct 10 ms 5496 KB Output is correct
24 Correct 10 ms 5496 KB Output is correct
25 Correct 11 ms 5496 KB Output is correct
26 Correct 14 ms 5880 KB Output is correct
27 Correct 14 ms 5880 KB Output is correct
28 Correct 14 ms 6636 KB Output is correct
29 Correct 13 ms 6392 KB Output is correct
30 Correct 14 ms 6284 KB Output is correct
31 Correct 15 ms 7292 KB Output is correct

Subtask #4
43.0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 5116 KB Output is correct
2 Correct 6 ms 5112 KB Output is correct
3 Correct 6 ms 5116 KB Output is correct
4 Correct 7 ms 5112 KB Output is correct
5 Correct 6 ms 5112 KB Output is correct
6 Correct 6 ms 5112 KB Output is correct
7 Correct 6 ms 5112 KB Output is correct
8 Correct 6 ms 5084 KB Output is correct
9 Correct 6 ms 5112 KB Output is correct
10 Correct 6 ms 5112 KB Output is correct
11 Correct 6 ms 5112 KB Output is correct
12 Correct 6 ms 5112 KB Output is correct
13 Correct 6 ms 5112 KB Output is correct
14 Correct 6 ms 5112 KB Output is correct
15 Correct 6 ms 5112 KB Output is correct
16 Correct 6 ms 5112 KB Output is correct
17 Correct 6 ms 5112 KB Output is correct
18 Correct 13 ms 5240 KB Output is correct
19 Correct 6 ms 5112 KB Output is correct
20 Correct 7 ms 5112 KB Output is correct
21 Correct 6 ms 5116 KB Output is correct
22 Correct 6 ms 5112 KB Output is correct
23 Correct 10 ms 5496 KB Output is correct
24 Correct 10 ms 5496 KB Output is correct
25 Correct 11 ms 5496 KB Output is correct
26 Correct 14 ms 5880 KB Output is correct
27 Correct 14 ms 5880 KB Output is correct
28 Correct 14 ms 6636 KB Output is correct
29 Correct 13 ms 6392 KB Output is correct
30 Correct 14 ms 6284 KB Output is correct
31 Correct 15 ms 7292 KB Output is correct
32 Correct 55 ms 9932 KB Output is correct
33 Correct 57 ms 9988 KB Output is correct
34 Correct 46 ms 9976 KB Output is correct
35 Correct 300 ms 25248 KB Output is correct
36 Correct 328 ms 25300 KB Output is correct
37 Correct 337 ms 25208 KB Output is correct
38 Correct 233 ms 35908 KB Output is correct
39 Correct 241 ms 33972 KB Output is correct
40 Correct 272 ms 33096 KB Output is correct
41 Correct 343 ms 40752 KB Output is correct