oj.uz

Submission #198267

# Submission time Handle Problem Language Result Execution time Memory
198267 2020-01-25T09:20:54 Z alishahali1382 Beads and wires (APIO14_beads) C++14
57 / 100
 1000 ms 29916 KB 
#include <bits/stdc++.h>
#pragma GCC optimize ("O2")
#pragma GCC optimize ("unroll-loops")
//#pragma GCC optimize("no-stack-protector,fast-math")

#define int long long

using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<pii, int> piii;
typedef pair<ll, ll> pll;
#define debug(x) cerr<<#x<<'='<<(x)<<endl;
#define debugp(x) cerr<<#x<<"= {"<<(x.first)<<", "<<(x.second)<<"}"<<endl;
#define debug2(x, y) cerr<<"{"<<#x<<", "<<#y<<"} = {"<<(x)<<", "<<(y)<<"}"<<endl;
#define debugv(v) cerr<<#v<<" : ";for (auto x:v) cerr<<x<<' ';cerr<<endl;
#define all(x) x.begin(), x.end()
#define pb push_back
#define kill(x) return cout<<x<<'\n', 0;

const ld eps=1e-7;
const int inf=2000000010;
const ll INF=10000000000000010LL;
const int mod = 1000000007;
const int MAXN = 200010, LOG=20;

int n, m, k, u, v, x, y, t, a, b, ans;
int dp[MAXN][2];
int sum[MAXN];
//int dp2[MAXN][2];
pii mx[MAXN][2];
vector<pii> G[MAXN];

void dfs1(int node, int par){
	dp[node][0]=0;
	dp[node][1]=-inf;
	for (pii p:G[node]) if (p.first!=par) dfs1(p.first, node);
	
	sum[node]=0;
	for (pii p:G[node]) if (p.first!=par) sum[node]+=max(dp[p.first][0], dp[p.first][1]+p.second);
	dp[node][0]=sum[node];
	
	mx[node][0]=mx[node][1]={-inf, 0};
	for (pii p:G[node]) if (p.first!=par){
		pii tmp={min(p.second, dp[p.first][0]-dp[p.first][1]), p.first};
		if (tmp>mx[node][1]) mx[node][1]=tmp;
		if (mx[node][1]>mx[node][0]) swap(mx[node][0], mx[node][1]);
	}
	dp[node][1]=sum[node]+mx[node][0].first;
	
	//dp[node][0]=sum;
	
}

void dfs2(int node, int par){
	ans=max(ans, dp[node][0]);
	int parw=0;
	for (pii p:G[node]) if (p.first==par) parw=p.second;
	
	for (pii p:G[node]) if (p.first!=par){
		int v=p.first, w=p.second;
		int nd0=dp[node][0], nd1=dp[node][1], ns=sum[node];
		int vd0=dp[v][0], vd1=dp[v][1], vs=sum[v];
		
		sum[node]-=max(dp[v][0], dp[v][1]+w);
		dp[node][0]=sum[node];
		dp[node][1]=-inf;
		
		dp[node][1]=sum[node]+mx[node][0].first;
		if (v==mx[node][0].second) dp[node][1]=sum[node]+mx[node][1].first;
		//if (node!=1) dp[node][0]=max(dp[node][0], sum[node]+min(parw, dp[par][0]-dp[par][1]));
		
		for (pii pp:G[node]) if (/*pp.first!=par && */pp.first!=v) dp[node][1]=max(dp[node][1], sum[node]+min(pp.second, dp[pp.first][0]-dp[pp.first][1]));
		
		sum[v]+=max(dp[node][0], dp[node][1]+w);
		dp[v][0]=sum[v];
		dp[v][1]=max(sum[v]+mx[v][0].first, sum[v]+min(w, dp[node][0]-dp[node][1]));
		
		dfs2(v, node);
		
		dp[node][0]=nd0;
		dp[node][1]=nd1;
		sum[node]=ns;
		dp[v][0]=vd0;
		dp[v][1]=vd1;
		sum[v]=vs;
	}
}

int32_t main(){
	ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
	//freopen("input.txt", "r", stdin);
	//freopen("output.txt", "w", stdout);
	cin>>n;
	//assert(n<=10000);
	for (int i=1; i<n; i++){
		cin>>u>>v>>x;
		G[u].pb({v, x});
		G[v].pb({u, x});
	}
	
	/*
	for (int i=1; i<=n; i++){
		for (int j=1; j<=n; j++) dp[j][0]=0, dp[j][1]=-inf, sum[j]=0;
		dfs1(i, i);
		ans=max(ans, dp[i][0]);
		//debug2(i, dp[i][0])
	}*/
	
	dfs1(1, 1);
	dfs2(1, 1);
	
	cout<<ans<<'\n';
	
	return 0;
}
/*
5
1 2 10
1 3 40
1 4 15
1 5 20


10
4 10 2
1 2 21
1 3 13
6 7 1
7 9 5
2 4 3
2 5 8
1 6 55
6 8 34

*/

Compilation message

beads.cpp: In function 'void dfs2(long long int, long long int)':
beads.cpp:58:6: warning: variable 'parw' set but not used [-Wunused-but-set-variable]
  int parw=0;
      ^~~~

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 5112 KB Output is correct
2 Correct 6 ms 4984 KB Output is correct
3 Correct 6 ms 4984 KB Output is correct
4 Correct 6 ms 4984 KB Output is correct
5 Correct 6 ms 4984 KB Output is correct
6 Correct 6 ms 4984 KB Output is correct
7 Correct 6 ms 5112 KB Output is correct
8 Correct 6 ms 4984 KB Output is correct
9 Correct 6 ms 4984 KB Output is correct
10 Correct 6 ms 5112 KB Output is correct
11 Correct 6 ms 4984 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 6 ms 5112 KB Output is correct
2 Correct 6 ms 4984 KB Output is correct
3 Correct 6 ms 4984 KB Output is correct
4 Correct 6 ms 4984 KB Output is correct
5 Correct 6 ms 4984 KB Output is correct
6 Correct 6 ms 4984 KB Output is correct
7 Correct 6 ms 5112 KB Output is correct
8 Correct 6 ms 4984 KB Output is correct
9 Correct 6 ms 4984 KB Output is correct
10 Correct 6 ms 5112 KB Output is correct
11 Correct 6 ms 4984 KB Output is correct
12 Correct 6 ms 5112 KB Output is correct
13 Correct 7 ms 5112 KB Output is correct
14 Correct 6 ms 5112 KB Output is correct
15 Correct 7 ms 4984 KB Output is correct
16 Correct 6 ms 5112 KB Output is correct
17 Correct 7 ms 5000 KB Output is correct
18 Correct 7 ms 5112 KB Output is correct
19 Correct 5 ms 5112 KB Output is correct
20 Correct 7 ms 5112 KB Output is correct
21 Correct 6 ms 4984 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 6 ms 5112 KB Output is correct
2 Correct 6 ms 4984 KB Output is correct
3 Correct 6 ms 4984 KB Output is correct
4 Correct 6 ms 4984 KB Output is correct
5 Correct 6 ms 4984 KB Output is correct
6 Correct 6 ms 4984 KB Output is correct
7 Correct 6 ms 5112 KB Output is correct
8 Correct 6 ms 4984 KB Output is correct
9 Correct 6 ms 4984 KB Output is correct
10 Correct 6 ms 5112 KB Output is correct
11 Correct 6 ms 4984 KB Output is correct
12 Correct 6 ms 5112 KB Output is correct
13 Correct 7 ms 5112 KB Output is correct
14 Correct 6 ms 5112 KB Output is correct
15 Correct 7 ms 4984 KB Output is correct
16 Correct 6 ms 5112 KB Output is correct
17 Correct 7 ms 5000 KB Output is correct
18 Correct 7 ms 5112 KB Output is correct
19 Correct 5 ms 5112 KB Output is correct
20 Correct 7 ms 5112 KB Output is correct
21 Correct 6 ms 4984 KB Output is correct
22 Correct 6 ms 5112 KB Output is correct
23 Correct 10 ms 5572 KB Output is correct
24 Correct 5 ms 5536 KB Output is correct
25 Correct 9 ms 5624 KB Output is correct
26 Correct 13 ms 6136 KB Output is correct
27 Correct 12 ms 6136 KB Output is correct
28 Correct 249 ms 6132 KB Output is correct
29 Correct 117 ms 6008 KB Output is correct
30 Correct 88 ms 6136 KB Output is correct
31 Correct 48 ms 6776 KB Output is correct

Subtask #4
0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 5112 KB Output is correct
2 Correct 6 ms 4984 KB Output is correct
3 Correct 6 ms 4984 KB Output is correct
4 Correct 6 ms 4984 KB Output is correct
5 Correct 6 ms 4984 KB Output is correct
6 Correct 6 ms 4984 KB Output is correct
7 Correct 6 ms 5112 KB Output is correct
8 Correct 6 ms 4984 KB Output is correct
9 Correct 6 ms 4984 KB Output is correct
10 Correct 6 ms 5112 KB Output is correct
11 Correct 6 ms 4984 KB Output is correct
12 Correct 6 ms 5112 KB Output is correct
13 Correct 7 ms 5112 KB Output is correct
14 Correct 6 ms 5112 KB Output is correct
15 Correct 7 ms 4984 KB Output is correct
16 Correct 6 ms 5112 KB Output is correct
17 Correct 7 ms 5000 KB Output is correct
18 Correct 7 ms 5112 KB Output is correct
19 Correct 5 ms 5112 KB Output is correct
20 Correct 7 ms 5112 KB Output is correct
21 Correct 6 ms 4984 KB Output is correct
22 Correct 6 ms 5112 KB Output is correct
23 Correct 10 ms 5572 KB Output is correct
24 Correct 5 ms 5536 KB Output is correct
25 Correct 9 ms 5624 KB Output is correct
26 Correct 13 ms 6136 KB Output is correct
27 Correct 12 ms 6136 KB Output is correct
28 Correct 249 ms 6132 KB Output is correct
29 Correct 117 ms 6008 KB Output is correct
30 Correct 88 ms 6136 KB Output is correct
31 Correct 48 ms 6776 KB Output is correct
32 Correct 54 ms 11140 KB Output is correct
33 Correct 51 ms 11168 KB Output is correct
34 Correct 56 ms 11128 KB Output is correct
35 Correct 322 ms 29796 KB Output is correct
36 Correct 293 ms 29916 KB Output is correct
37 Correct 285 ms 29816 KB Output is correct
38 Execution timed out 1082 ms 29172 KB Time limit exceeded
39 Halted 0 ms 0 KB -