Submission #487078

# Submission time Handle Problem Language Result Execution time Memory
487078 2021-11-14T04:06:02 Z kiomi Shymbulak (IZhO14_shymbulak) C++17
50 / 100
1500 ms 30956 KB
//#pragma GCC target ("avx2")
//#pragma GCC optimization ("Ofast")
//#pragma GCC optimization ("unroll-loops")

//#pragma comment(linker,"/stack:200000000")
//#pragma GCC optimize("Ofast")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")

//order_of_key(k): Number of items strictly smaller than k .
//find_by_order(k): K-th element in a set (counting from zero).
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>

#define full(x,n) x,x+n+1
#define full(x) x.begin(),x.end()
#define finish return 0

#define putb push_back
#define f first
#define s second

//logx(a^n)=loga(a^n)/logx(a)
//logx(a*b)=logx(a)+logx(b)
//logx(y)=log(y)/log(x)
//logb(n)=loga(n)/loga(b)

#define ordered_set tree<ll,null_type,less<ll>,rb_tree_tag,tree_order_statistics_node_update>
#define putf push_front
#define gainb pop_back

//(a+b)^n=sum of C(n,i)*a^i*b^(n-i) 0<=i<=n
//(a-b)^n=sum of C(n,i)*a^i*b^(n-i) for even i-for odd i

#define gainf pop_front
#define len(x) (int)x.size()

// 1/b%mod=b^(m-2)%mod
// (a>>x)&1==0
// a^b=(a+b)-2(a&b)

typedef double db;
typedef long long ll;
#define int long long

//sum of squares n*(n+1)*(2n+1)/6
//sum of cubes [n*(n+1)/2]^2
//sum of squares for odds n*(4*n*n-1)/3
//sum of cubes for odds n*n*(2*n*n-1)

const int ary=1e6+5;
const ll mod=1e9+7;
const ll inf=1e18;

using namespace std;
using namespace __gnu_pbds;
int n,m,c[ary],p[ary],e[ary],d[ary],dm[ary],k[ary],md[4*ary],diam,ans,q[ary];
vector<int> g[ary];
vector< pair<int,int> > w;
pair<int,int> r[ary];
pair<int,int> t[4*ary];
bool dfs(int v=1,int pr=0){
	c[v]=1;
	for(int i=0;i<len(g[v]);i++){
		int to=g[v][i];
		if(to==pr){
			continue;
		}
		if(c[to]==0){
			p[to]=v;
			if(dfs(to,v)){
				return 1;
			}
		}
		else if(c[to]==1){
			int u=v;
			while(1){
				m++;
				q[m]=u;
				k[u]=m;
				if(u==to){
					break;
				}
				u=p[u];
			}
			return 1;
		}
	}
	c[v]=2;
	return 0;
}
void go(int v,int pr=0){
	dm[v]=d[v]=d[pr]+1;
	e[v]=1;
	for(int i=0;i<len(g[v]);i++){
		int to=g[v][i];
		if(to==pr||k[to]){
			continue;
		}
		go(to,v);
		if(dm[v]<dm[to]){
			e[v]=0;
			dm[v]=dm[to];
		}
		if(dm[v]==dm[to]){
			e[v]+=e[to];
		}
	}
}
void push(int v,bool ok){
	if(md[v]!=0){
		t[v].f+=md[v];
		if(ok){
			md[v*2]+=md[v];
			md[v*2+1]+=md[v];
		}
		md[v]=0;
	}
}
void build(int v=1,int tl=1,int tr=m){
	if(tl==tr){
		t[v]={dm[q[tl]]+min(tl-1,m-(tl-1)),e[q[tl]]};
		return;
	}
	int tm=(tl+tr)/2;
	build(v*2,tl,tm);
	build(v*2+1,tm+1,tr);
	if(t[v*2].f<t[v*2+1].f){
		t[v]=t[v*2+1];
	}
	else if(t[v*2].f>t[v*2+1].f){
		t[v]=t[v*2];
	}
	else{
		t[v]={t[v*2].f,t[v*2].s+t[v*2+1].s};
	}
}
void upd(int l,int r,int x,int v=1,int tl=1,int tr=m){
	push(v,(tl<tr));
	if(tr<l||tl>r||l>r){
		return;
	}
	if(l<=tl&&tr<=r){
		md[v]+=x;
		push(v,(tl<tr));
		return;
	}
	int tm=(tl+tr)/2;
	upd(l,r,x,v*2,tl,tm);
	upd(l,r,x,v*2+1,tm+1,tr);
	if(t[v*2].f<t[v*2+1].f){
		t[v]=t[v*2+1];
	}
	else if(t[v*2].f>t[v*2+1].f){
		t[v]=t[v*2];
	}
	else{
		t[v]={t[v*2].f,t[v*2].s+t[v*2+1].s};
	}
}
pair<int,int> get(int l,int r,int v=1,int tl=1,int tr=m){
	push(v,(tl<tr));
	if(tr<l||r<tl||l>r){
		return {0,0};
	}
	if(l<=tl&&tr<=r){
		return t[v];
	}
	int tm=(tl+tr)/2;
	pair<int,int> a=get(l,r,v*2,tl,tm);
	pair<int,int> b=get(l,r,v*2+1,tm+1,tr);
	if(a.f<b.f){
		return b;
	}
	else if(a.f>b.f){
		return a;
	}
	else{
		return {a.f,a.s+b.s};
	}
}
void func(int i,int x,int y){
	if(i+x-1<=m){
		upd(i,i+x-1,y);
	}
	else{
		upd(i,m,y);
		upd(1,x-(m-i+1),y);
	}
}
void fill(int u,int v,int pr=0,int d=0,int cnt=0){
	if(diam<d){
		diam=d;
		ans=0;
	}
	if(diam==d&&u<v){
		ans++;
	}
	for(int i=0;i<len(g[v]);i++){
		int to=g[v][i];
		if(to==pr||cnt+(k[to]>0)==2){
			continue;
		}
		fill(u,to,v,d+1,cnt+(k[to]>0));
	}
}
void tea(int v,int pr=0){
	fill(v,v);
	for(int i=0;i<len(g[v]);i++){
		int to=g[v][i];
		if(to==pr||k[to]){
			continue;
		}
		tea(to,v);
	}
	/*w.clear();
	for(int i=0;i<len(g[v]);i++){
		int to=g[v][i];
		if(to==pr||k[to]){
			continue;
		}
		tea(to,v);
		w.push_back({dm[to],e[to]});
	}
	sort(full(w));
	reverse(full(w));
	if(len(w)==1){
		if(diam<w.back().f){
			diam=w.back().f;
			ans=0;
		}
		if(diam==w.back().f){
			ans+=w.back().s;
		}
	}
	else if(len(w)>1){
		if(diam<w[0].f+w[1].f){
			diam=w[0].f+w[1].f;
			ans=0;
		}
		if(diam==w[0].f+w[1].f){
			int cnt=w[0].s;
			for(int i=1;i<len(w);i++){
				if(w[i].f==w[1].f){
					ans+=cnt*w[i].s;
				}
				if(w[i].f==w[0].f){
					cnt+=w[i].s;
				}
			}
		}
	}*/
}
main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);cout.tie(0);
	cin>>n;
	for(int i=1;i<=n;i++){
		int a,b;
		cin>>a>>b;
		g[a].push_back(b);
		g[b].push_back(a);
	}
	dfs();
	d[0]=-1;
	for(int i=1;i<=m;i++){
		go(q[i]);
	}
	for(int i=1;i<=n;i++){
		if(k[i]){
			continue;
		}
		fill(i,i);
	}
	for(int i=1;i<=m;i++){
		if(i==1){
			build();
			continue;
		}
			int x=m/2;
			int y=m-x;
			func(i,x,-1);
			if(y==x){
				func(i+x-m*(i+x>m),y,1);
			}
			else{
				func(i+x+1-m*(i+x+1>m),y-1,1);
			}
		r[i]=get(1,i-1);
		if(diam<r[i].f+dm[q[i]]){
			diam=r[i].f+dm[q[i]];
			ans=0;
		}
		if(diam==r[i].f+dm[q[i]]){
			if(m%2==0&&i-m/2>=1){
				if(diam==dm[q[i]]+dm[q[i-m/2]]+m/2){
					ans+=e[q[i]]*e[q[i-m/2]];
				}
			}
			ans+=e[q[i]]*r[i].s;
		}
		//tea(q[i]);
		//cout<<i<<" "<<q[i]<<" "<<r[i].f<<" "<<r[i].s<<" "<<e[q[i]]<<" "<<dm[q[i]]<<" "<<d[q[i]]<<" "<<m%2<<" "<<i-m/2<<" "<<diam<<" "<<dm[q[i-m/2]]<<" "<<e[q[i-m/2]]<<"\n";
	}
	cout<<ans;
}

Compilation message

shymbulak.cpp:15: warning: "full" redefined
   15 | #define full(x) x.begin(),x.end()
      | 
shymbulak.cpp:14: note: this is the location of the previous definition
   14 | #define full(x,n) x,x+n+1
      | 
shymbulak.cpp:253:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
  253 | main(){
      | ^~~~
# Verdict Execution time Memory Grader output
1 Correct 12 ms 23872 KB Output is correct
2 Correct 16 ms 23756 KB Output is correct
3 Correct 15 ms 23756 KB Output is correct
4 Correct 13 ms 23816 KB Output is correct
5 Correct 13 ms 23756 KB Output is correct
6 Correct 12 ms 23756 KB Output is correct
7 Correct 13 ms 23816 KB Output is correct
8 Correct 12 ms 23756 KB Output is correct
9 Correct 12 ms 23876 KB Output is correct
10 Correct 12 ms 23756 KB Output is correct
11 Correct 13 ms 23856 KB Output is correct
12 Correct 12 ms 23864 KB Output is correct
13 Correct 12 ms 23884 KB Output is correct
14 Correct 13 ms 23828 KB Output is correct
15 Correct 12 ms 23928 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 13 ms 24016 KB Output is correct
2 Correct 18 ms 23884 KB Output is correct
3 Correct 13 ms 23960 KB Output is correct
4 Correct 14 ms 23936 KB Output is correct
5 Correct 30 ms 24268 KB Output is correct
6 Correct 218 ms 24256 KB Output is correct
7 Correct 427 ms 24288 KB Output is correct
8 Correct 369 ms 24260 KB Output is correct
9 Correct 19 ms 24200 KB Output is correct
10 Correct 92 ms 24196 KB Output is correct
# Verdict Execution time Memory Grader output
1 Execution timed out 1570 ms 30956 KB Time limit exceeded
2 Halted 0 ms 0 KB -