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답안 #386428

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
386428 2021-04-06T14:13:50 Z kshitij_sodani Islands (IOI08_islands) C++14
80 / 100
 801 ms 131076 KB 
//#pragma GCC optimize("Ofast,unroll-loops")
#include <bits/stdc++.h>
using namespace std;
typedef long long llo;
#define mp make_pair
#define pb push_back
#define a first 
#define b second
#define endl '\n'
 
 
llo n;
vector<pair<int,int>> adj[1000001];

int par[1000001];
int find(int no){
	if(par[no]==no){
		return no;
	}
	par[no]=find(par[no]);
	return par[no];
}
llo dp[1000001][2];
pair<int,int> cur;
vector<pair<int,int>> pp;
vector<pair<int,int>> xx;

bool vis[1000001];
 
vector<int> tt;
void dfs(int no,int par2=-1){
	
	if(no==cur.b){
		pp=xx;
	}
	tt.pb(no);
	for(auto j:adj[no]){
		/*if(j.a==cur.a and no==cur.b){
			continue;
		}
		if(j.a==cur.b and no==cur.a){
			continue;
		}*/
		
		if(j.a!=par2){
			xx.pb({j.a,j.b});
			dfs(j.a,no);
			xx.pop_back();
		}
	}
}
 
llo maa=0;
 
void dfs2(llo no,llo par2=-1){
	dp[no][0]=0;
	dp[no][1]=0;
	//vector<llo> ss;
	//llo su=0;
 	llo ma=0;
 	llo ma2=0;
	for(auto j:adj[no]){
		if(vis[j.a]){
			continue;
		}
		if(j.a!=par2){
			dfs2(j.a,no);
	//		dp[no][0]=max(dp[no][0],j.b+dp[j.a][0]);

			if(dp[j.a][0]+j.b>=ma){
				ma2=ma;
				ma=dp[j.a][0]+j.b;
			}
			else if(dp[j.a][0]+j.b>=ma2){
				ma2=dp[j.a][0]+j.b;
			}
			//su+=dp[j.a][1];
			//ss.pb(dp[j.a][0]+j.b);
		}
	}
	//sort(ss.begin(),ss.end());
	//reverse(ss.begin(),ss.end());
	dp[no][1]=ma+ma2;
	dp[no][0]=ma;


	/*for(llo i=0;i<ss.size();i++){
		if(i==2){
			break;
		}
 
		if(i==0){
			if(ss[i]>=0){
				dp[no][0]+=ss[i];
			}
		}
		if(ss[i]>=0){
			dp[no][1]+=ss[i];
		}
	}*/
	//dp[no][1]=max(dp[no][1],dp[no][0]);
	maa=max(maa,dp[no][1]);
}
int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cin>>n;
	for(llo i=0;i<n;i++){
		par[i]=i;
	}
	vector<pair<pair<int,int>,llo>> ed;
	for(llo i=0;i<n;i++){
		llo aa,cc;
		cin>>aa>>cc;
		aa--;
		llo x=find(i);
		llo y=find(aa);
		if(x!=y){
			par[x]=y;
			adj[i].pb({aa,cc});
			adj[aa].pb({i,cc});
		}
		else{
			ed.pb({{i,aa},cc});
		}
	}
	llo ans=0;
	for(auto j:ed){
		cur=j.a;
		llo cost=0;
		tt.clear();
		dfs(j.a.a);
		pp.pb({cur.a,j.b});
		for(auto i:pp){
			vis[i.a]=1;
		}
	/*	vector<pair<pair<int,int>,llo>> pc;
		pc.pb(j);
 
		for(auto i:tt){
			for(auto k:adj[i]){
				if(vis[k.a]+vis[i]<2){
					//adj2[i].pb(k);
				}
				else{
					if(k.a<i){
						pc.pb({{i,k.a},k.b});
					}
				}
			}
		}
*/
		maa=0;
		for(auto i:tt){
				for(auto k:adj[i]){
					if(vis[k.a]+vis[i]<2){
					//	adj2[i].pb(k);
					}
					else{
 
					}
				}
			}
		for(auto i:pp){
			dfs2(i.a);
		}
		cost=max(cost,maa);
	
		llo xx=pp.size();
		multiset<llo> zz;
		for(int i=0;i<xx;i++){
			pp.pb(pp[i]);
		}
	//	vector<llo> xd;
		llo su2=0;
		llo su3=0;
		for(llo i=0;i<pp.size();i++){
			if(i>=xx){
				su3+=pp[i-xx].b;
				auto jj=zz.find(dp[pp[i-xx].a][0]-su3);
				zz.erase(jj);
			}
			su2+=pp[i].b;
			if(zz.size()){
				auto jj=zz.end();
				jj--;
				cost=max(cost,dp[pp[i].a][0]+su2+(*jj));
			}
			if(i<xx){
				//xd.pb(dp[pp[i].a][0]-su2);
				zz.insert(dp[pp[i].a][0]-su2);
			}
		}
		ans+=cost;
 
 
 
 
 
 
 
 
	}
	cout<<ans<<endl;
 
 
 
 
 
 
 
	return 0;
}

Compilation message

islands.cpp: In function 'int main()':
islands.cpp:177:16: warning: comparison of integer expressions of different signedness: 'llo' {aka 'long long int'} and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  177 |   for(llo i=0;i<pp.size();i++){
      |               ~^~~~~~~~~~

Subtask #1
33.0 / 33.0

# 결과 실행 시간 메모리 Grader output
1 Correct 16 ms 23916 KB Output is correct
2 Correct 16 ms 23916 KB Output is correct
3 Correct 16 ms 23916 KB Output is correct
4 Correct 15 ms 23788 KB Output is correct
5 Correct 16 ms 23788 KB Output is correct
6 Correct 18 ms 23916 KB Output is correct
7 Correct 16 ms 23788 KB Output is correct
8 Correct 15 ms 23788 KB Output is correct
9 Correct 16 ms 23788 KB Output is correct
10 Correct 16 ms 23788 KB Output is correct
11 Correct 15 ms 23916 KB Output is correct

Subtask #2
3.0 / 3.0

# 결과 실행 시간 메모리 Grader output
1 Correct 17 ms 24044 KB Output is correct
2 Correct 17 ms 24064 KB Output is correct

Subtask #3
4.0 / 4.0

# 결과 실행 시간 메모리 Grader output
1 Correct 16 ms 23916 KB Output is correct
2 Correct 18 ms 24428 KB Output is correct

Subtask #4
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 24 ms 25068 KB Output is correct
2 Correct 37 ms 28368 KB Output is correct
3 Correct 26 ms 25324 KB Output is correct
4 Correct 21 ms 24556 KB Output is correct

Subtask #5
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 46 ms 30008 KB Output is correct
2 Correct 62 ms 32340 KB Output is correct

Subtask #6
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 98 ms 39008 KB Output is correct
2 Correct 132 ms 47620 KB Output is correct
3 Correct 169 ms 61636 KB Output is correct

Subtask #7
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 175 ms 48760 KB Output is correct
2 Correct 307 ms 84728 KB Output is correct
3 Correct 361 ms 95004 KB Output is correct
4 Correct 402 ms 126028 KB Output is correct

Subtask #8
0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 346 ms 90568 KB Output is correct
2 Runtime error 801 ms 131076 KB Execution killed with signal 9
3 Halted 0 ms 0 KB -

Subtask #9
0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Runtime error 380 ms 131072 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -