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Submission #337823

# Submission time Handle Problem Language Result Execution time Memory
337823 2020-12-21T18:36:45 Z Kerim Shymbulak (IZhO14_shymbulak) C++17
100 / 100
 279 ms 38740 KB 
#include "bits/stdc++.h"
#define MAXN 200009
#define INF 1000000007
#define mp(x,y) make_pair(x,y)
#define all(v) v.begin(),v.end()
#define pb(x) push_back(x)
#define wr cout<<"----------------"<<endl;
#define ppb() pop_back()
#define tr(ii,c) for(__typeof((c).begin()) ii=(c).begin();ii!=(c).end();ii++)
#define ff first
#define ss second
#define my_little_dodge 46
#define debug(x)  cerr<< #x <<" = "<< x<<endl;
using namespace std;
 
typedef long long ll;
typedef pair<int,ll> PII;
template<class T>bool umin(T& a,T b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool umax(T& a,T b){if(a<b){a=b;return 1;}return 0;}
vector<PII>g[MAXN];
stack<int>st;
vector<int>adj[MAXN],v;
int vis[MAXN];
void dfs1(int nd,int pr){
	if(!v.empty())
		return;
	if(vis[nd]){
		while(!st.empty() and st.top()!=nd)
			v.pb(st.top()),st.pop();
		v.pb(nd);
		return;
	}
	st.push(nd);
	vis[nd]=1;
	tr(it,g[nd])
		if(it->ss!=pr)
			dfs1(it->ff,it->ss);
	if(!st.empty()) st.pop();
}
PII dp[MAXN],ans;
PII merge(PII x,PII y){
	if(x.ff>y.ff)
		return x;
	if(y.ff>x.ff)
		return y;
	return mp(x.ff,x.ss+y.ss);
}
void dfs(int nd,int pr){
	dp[nd]=mp(0,1);
	vector<PII>v;
	tr(it,adj[nd])
		if(*it!=pr and !vis[*it]){
			dfs(*it,nd);
			v.pb(dp[*it]);
			dp[nd]=merge(dp[nd],dp[*it]);
		}
	sort(all(v));
	if(int(v.size())>=2){
		PII b=v[v.size()-2],a=v[v.size()-1],c=mp(a.ff+b.ff,0);
		for(int i=0;i<int(v.size());i++)
			if(v[i].ff==b.ff)
				c.ss+=v[i].ss;
		if(a.ff!=b.ff){
			c.ss*=a.ss;
			ans=merge(ans,c);
		}	
		else{
			c.ss*=c.ss;
			for(int i=0;i<int(v.size());i++)
				if(v[i].ff==b.ff)
					c.ss-=v[i].ss*v[i].ss;
			c.ss/=2;
			ans=merge(ans,c);
		}
	}
	else
		ans=merge(ans,dp[nd]);
	dp[nd].ff++;
}
map<int,ll>a;
int main(){
    //freopen("file.in", "r", stdin);
	int n;
	scanf("%d",&n);
	for(int i=1;i<=n;i++){
		int u,v;
		scanf("%d%d",&u,&v);
		g[u].pb(mp(v,i));adj[u].pb(v);
		g[v].pb(mp(u,i));adj[v].pb(u);
	}
	dfs1(1,-1);int sz=int(v.size());
	memset(vis,0,sizeof vis);
	tr(it,v)
		vis[*it]=1;
	vector<PII>g;
	tr(it,v)
		dfs(*it,-1),g.pb(mp(dp[*it].ff-1,dp[*it].ss));
	int p=0;
	for(int i=0;i<sz-1;i++){
		while(p<sz and p+p<=sz+i+i)
			a[g[p].ff+p]+=g[p].ss,p++;
		a[g[i].ff+i]-=g[i].ss;
		if(!a[g[i].ff+i])
			a.erase(g[i].ff+i);
		PII tmp=*a.rbegin();
		ans=merge(ans,mp(tmp.ff+g[i].ff-i,g[i].ss*tmp.ss));
	}p=sz-1;a.clear();
	for(int i=sz-1;i>=0;i--){
		while(p+p>=sz+i+i)
			a[g[p].ff+sz-p]+=g[p].ss,p--;	
		if(a.size()){
			PII tmp=*a.rbegin();
			ans=merge(ans,mp(tmp.ff+g[i].ff+i,g[i].ss*tmp.ss));	
		}
	}
	printf("%lld\n",ans.ss);
	return 0;
}

Compilation message

shymbulak.cpp: In function 'int main()':
shymbulak.cpp:84:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   84 |  scanf("%d",&n);
      |  ~~~~~^~~~~~~~~
shymbulak.cpp:87:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   87 |   scanf("%d%d",&u,&v);
      |   ~~~~~^~~~~~~~~~~~~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 10476 KB Output is correct
2 Correct 7 ms 10476 KB Output is correct
3 Correct 7 ms 10476 KB Output is correct
4 Correct 7 ms 10476 KB Output is correct
5 Correct 7 ms 10476 KB Output is correct
6 Correct 7 ms 10476 KB Output is correct
7 Correct 7 ms 10476 KB Output is correct
8 Correct 7 ms 10476 KB Output is correct
9 Correct 7 ms 10476 KB Output is correct
10 Correct 7 ms 10476 KB Output is correct
11 Correct 7 ms 10476 KB Output is correct
12 Correct 8 ms 10476 KB Output is correct
13 Correct 7 ms 10476 KB Output is correct
14 Correct 7 ms 10604 KB Output is correct
15 Correct 7 ms 10604 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 10604 KB Output is correct
2 Correct 7 ms 10604 KB Output is correct
3 Correct 9 ms 10604 KB Output is correct
4 Correct 8 ms 10604 KB Output is correct
5 Correct 10 ms 10988 KB Output is correct
6 Correct 10 ms 11244 KB Output is correct
7 Correct 12 ms 10988 KB Output is correct
8 Correct 11 ms 10988 KB Output is correct
9 Correct 10 ms 10988 KB Output is correct
10 Correct 10 ms 10988 KB Output is correct

Subtask #3
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 141 ms 20588 KB Output is correct
2 Correct 145 ms 20672 KB Output is correct
3 Correct 81 ms 24936 KB Output is correct
4 Correct 70 ms 21612 KB Output is correct
5 Correct 72 ms 21612 KB Output is correct
6 Correct 279 ms 31852 KB Output is correct
7 Correct 203 ms 26496 KB Output is correct
8 Correct 139 ms 32620 KB Output is correct
9 Correct 147 ms 32876 KB Output is correct
10 Correct 127 ms 33772 KB Output is correct
11 Correct 215 ms 37604 KB Output is correct
12 Correct 218 ms 38740 KB Output is correct