oj.uz

Submission #298761

# Submission time Handle Problem Language Result Execution time Memory
298761 2020-09-14T00:52:18 Z errorgorn Beads and wires (APIO14_beads) C++14
100 / 100
 855 ms 125296 KB 
//雪花飄飄北風嘯嘯
//天地一片蒼茫

#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,fma")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/rope>
using namespace std;
using namespace __gnu_pbds;
using namespace __gnu_cxx;
#define ll long long
#define ii pair<ll,ll>
#define iii pair<ii,ll>
#define fi first
#define se second
#define endl '\n'
#define debug(x) cout << #x << " is " << x << endl

#define rep(x,start,end) for(auto x=(start)-((start)>(end));x!=(end)-((start)>(end));((start)<(end)?x++:x--))
#define all(x) (x).begin(),(x).end()
#define sz(x) (int)(x).size()

#define indexed_set tree<ll,null_type,less<ll>,rb_tree_tag,tree_order_statistics_node_update>
//change less to less_equal for non distinct pbds, but erase will bug

mt19937 rng(chrono::system_clock::now().time_since_epoch().count());

struct custom_hash {
    typedef unsigned long long ull;
    const ull FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
    static ull splitmix64(ull x) {
        // http://xorshift.di.unimi.it/splitmix64.c
        x += 0x9e3779b97f4a7c15;
        x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
        x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
        return x ^ (x >> 31);
    }

    size_t operator()(ll x) const {
        return splitmix64(x + FIXED_RANDOM);
    }
    size_t operator()(const pair<int,int> &i)const{
        return splitmix64((((ll)i.first)^(((ll)i.second)<<32))+FIXED_RANDOM);
    }
};


int n;
vector<ii> al[200005];
unordered_map<ii,ii,custom_hash> memo;
unordered_map<ii,ll,custom_hash> w;

ii s[200005];
int pa[200005];
ll tot[200005];

ii dp(int i,int p){
	if (memo.count(ii(i,p))) return memo[ii(i,p)];
	
	ii res;
	if (!pa[i]){
		for (auto &it:al[i]){
			if (it.fi==p) continue;
			
			auto temp=dp(it.fi,i);
			ll val=max(temp.fi,temp.se+it.se);
			
			tot[i]+=val;
			
			ll vv=temp.fi+it.se-val;
			if (s[i].fi<vv){
				s[i].se=s[i].fi;
				s[i].fi=vv;
			}
			else if (s[i].se<vv){
				s[i].se=vv;
			}
		}
		res=ii(tot[i],tot[i]+s[i].fi);
		pa[i]=p;
	}
	else{
		if (pa[i]!=-1){
			auto temp=dp(pa[i],i);
			ll ww=w[ii(i,pa[i])];
			ll val=max(temp.fi,temp.se+ww);
			
			tot[i]+=val;
			
			ll vv=temp.fi+ww-val;
			if (s[i].fi<vv){
				s[i].se=s[i].fi;
				s[i].fi=vv;
			}
			else if (s[i].se<vv){
				s[i].se=vv;
			}
			pa[i]=-1;
		}
		
		ii temp;
		ll ww;
		ll val;
		ll vv;
		if (p!=-1){
			temp=dp(p,i);
			ww=w[ii(i,p)];
			val=max(temp.fi,temp.se+ww);
			
			tot[i]-=val;
			vv=temp.fi+ww-val;
		}
		
		res=ii(tot[i],tot[i]+(s[i].fi==vv?s[i].se:s[i].fi));
		
		if (p!=-1){
			tot[i]+=val;
		}
	}
	
	return memo[ii(i,p)]=res;
}

int main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	cin.exceptions(ios::badbit | ios::failbit);
	
	memo.reserve(4096);
	memo.max_load_factor(0.25);
	
	w.reserve(4096);
	w.max_load_factor(0.25);
	
	rep(x,0,200005) s[x]=ii(-1e9,-1e9);
	
	cin>>n;
	
	int a,b,c;
	rep(x,1,n){
		cin>>a>>b>>c;
		
		al[a].push_back(ii(b,c));
		al[b].push_back(ii(a,c));
		w[ii(a,b)]=c;
		w[ii(b,a)]=c;
	}
	
	ll ans=0;
	rep(x,1,n+1) ans=max(ans,dp(x,-1).fi);
	
	cout<<ans<<endl;
}

Compilation message

beads.cpp: In function 'std::pair<long long int, long long int> dp(int, int)':
beads.cpp:118:36: warning: 'vv' may be used uninitialized in this function [-Wmaybe-uninitialized]
  118 |   res=ii(tot[i],tot[i]+(s[i].fi==vv?s[i].se:s[i].fi));
      |                        ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 8192 KB Output is correct
2 Correct 6 ms 8192 KB Output is correct
3 Correct 6 ms 8192 KB Output is correct
4 Correct 6 ms 8192 KB Output is correct
5 Correct 6 ms 8192 KB Output is correct
6 Correct 6 ms 8192 KB Output is correct
7 Correct 6 ms 8192 KB Output is correct
8 Correct 6 ms 8192 KB Output is correct
9 Correct 6 ms 8192 KB Output is correct
10 Correct 6 ms 8192 KB Output is correct
11 Correct 6 ms 8192 KB Output is correct
12 Correct 6 ms 8192 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 8192 KB Output is correct
2 Correct 6 ms 8192 KB Output is correct
3 Correct 6 ms 8192 KB Output is correct
4 Correct 6 ms 8192 KB Output is correct
5 Correct 6 ms 8192 KB Output is correct
6 Correct 6 ms 8192 KB Output is correct
7 Correct 6 ms 8192 KB Output is correct
8 Correct 6 ms 8192 KB Output is correct
9 Correct 6 ms 8192 KB Output is correct
10 Correct 6 ms 8192 KB Output is correct
11 Correct 6 ms 8192 KB Output is correct
12 Correct 6 ms 8192 KB Output is correct
13 Correct 6 ms 8320 KB Output is correct
14 Correct 6 ms 8320 KB Output is correct
15 Correct 6 ms 8448 KB Output is correct
16 Correct 6 ms 8320 KB Output is correct
17 Correct 6 ms 8320 KB Output is correct
18 Correct 6 ms 8320 KB Output is correct
19 Correct 6 ms 8448 KB Output is correct
20 Correct 6 ms 8320 KB Output is correct
21 Correct 6 ms 8320 KB Output is correct
22 Correct 6 ms 8320 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 8192 KB Output is correct
2 Correct 6 ms 8192 KB Output is correct
3 Correct 6 ms 8192 KB Output is correct
4 Correct 6 ms 8192 KB Output is correct
5 Correct 6 ms 8192 KB Output is correct
6 Correct 6 ms 8192 KB Output is correct
7 Correct 6 ms 8192 KB Output is correct
8 Correct 6 ms 8192 KB Output is correct
9 Correct 6 ms 8192 KB Output is correct
10 Correct 6 ms 8192 KB Output is correct
11 Correct 6 ms 8192 KB Output is correct
12 Correct 6 ms 8192 KB Output is correct
13 Correct 6 ms 8320 KB Output is correct
14 Correct 6 ms 8320 KB Output is correct
15 Correct 6 ms 8448 KB Output is correct
16 Correct 6 ms 8320 KB Output is correct
17 Correct 6 ms 8320 KB Output is correct
18 Correct 6 ms 8320 KB Output is correct
19 Correct 6 ms 8448 KB Output is correct
20 Correct 6 ms 8320 KB Output is correct
21 Correct 6 ms 8320 KB Output is correct
22 Correct 6 ms 8320 KB Output is correct
23 Correct 15 ms 11096 KB Output is correct
24 Correct 15 ms 11224 KB Output is correct
25 Correct 14 ms 11096 KB Output is correct
26 Correct 26 ms 13980 KB Output is correct
27 Correct 26 ms 13980 KB Output is correct
28 Correct 27 ms 13980 KB Output is correct
29 Correct 26 ms 13852 KB Output is correct
30 Correct 27 ms 13980 KB Output is correct
31 Correct 27 ms 14492 KB Output is correct

Subtask #4
43.0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 8192 KB Output is correct
2 Correct 6 ms 8192 KB Output is correct
3 Correct 6 ms 8192 KB Output is correct
4 Correct 6 ms 8192 KB Output is correct
5 Correct 6 ms 8192 KB Output is correct
6 Correct 6 ms 8192 KB Output is correct
7 Correct 6 ms 8192 KB Output is correct
8 Correct 6 ms 8192 KB Output is correct
9 Correct 6 ms 8192 KB Output is correct
10 Correct 6 ms 8192 KB Output is correct
11 Correct 6 ms 8192 KB Output is correct
12 Correct 6 ms 8192 KB Output is correct
13 Correct 6 ms 8320 KB Output is correct
14 Correct 6 ms 8320 KB Output is correct
15 Correct 6 ms 8448 KB Output is correct
16 Correct 6 ms 8320 KB Output is correct
17 Correct 6 ms 8320 KB Output is correct
18 Correct 6 ms 8320 KB Output is correct
19 Correct 6 ms 8448 KB Output is correct
20 Correct 6 ms 8320 KB Output is correct
21 Correct 6 ms 8320 KB Output is correct
22 Correct 6 ms 8320 KB Output is correct
23 Correct 15 ms 11096 KB Output is correct
24 Correct 15 ms 11224 KB Output is correct
25 Correct 14 ms 11096 KB Output is correct
26 Correct 26 ms 13980 KB Output is correct
27 Correct 26 ms 13980 KB Output is correct
28 Correct 27 ms 13980 KB Output is correct
29 Correct 26 ms 13852 KB Output is correct
30 Correct 27 ms 13980 KB Output is correct
31 Correct 27 ms 14492 KB Output is correct
32 Correct 178 ms 34912 KB Output is correct
33 Correct 173 ms 34936 KB Output is correct
34 Correct 165 ms 35040 KB Output is correct
35 Correct 801 ms 116464 KB Output is correct
36 Correct 796 ms 120172 KB Output is correct
37 Correct 794 ms 120048 KB Output is correct
38 Correct 775 ms 119348 KB Output is correct
39 Correct 789 ms 119276 KB Output is correct
40 Correct 790 ms 119360 KB Output is correct
41 Correct 855 ms 125296 KB Output is correct