Submission #419601

#	Time	Username	Problem	Language	Result	Execution time	Memory
419601		keta_tsimakuridze	Zagrade (COI17_zagrade)	C++14	10 / 100	175 ms	27332 KiB

zagrade

#include<bits/stdc++.h>
#define f first
#define s second
#define int long long
using namespace std;
const int N=2e5+5,mod=1e9+7;
int t,ans,sz[N],c[N],fix[N],n,centroid,ans_;
vector<int>V[N];
map<int,int> cnt;
void get_szs(int u,int p){
	sz[u] = 1;
	for(int i=0;i<V[u].size();i++){
		if(V[u][i]==p || fix[V[u][i]]) continue;
		get_szs(V[u][i],u);
		sz[u] += sz[V[u][i]];
	}
}
int find_centroid(int u,int p,int Sz){
	for(int i=0;i<V[u].size();i++){
		if(V[u][i]==p || fix[V[u][i]]) continue;
		if(sz[V[u][i]] >Sz/2) return find_centroid(V[u][i],u,Sz);
	}
	return u;
}
void half2(int u,int p,int cur,int mn,int x,int y) {
	// # of vertices   such that  

	cur += c[u];
	x+=(c[u]==1);
	mn = min(mn,cur);
	y+=(c[u]==-1);
//	y x
	if(y-x >= abs(mn))ans += cnt[y-x];
	if(mn+c[centroid] >= 0 && cur+c[centroid] == 0 )  ans_++;
//	cout<<u<<" "<<cur<<" "<<mn<<" "<<x<<" "<<y<<endl;
	for(int i=0;i<V[u].size();i++){
		if(V[u][i] == p || fix[V[u][i]]) continue;
		// end
		half2(V[u][i],u,cur,mn,x,y);
	}
}
void half1(int u,int p,int cur,int mx,int x,int y) {
	
	cur += c[u];
	x+=(c[u]==1);
	mx = max(mx,cur); 
	y+=(c[u]==-1); //cout<<u<<" "<<x<<" "<<y<<" "<<mx<<endl;
	if(cur-mx >= 0) cnt[x-y]++;
	if(cur-mx >= 0 && cur==0) ans_++;
	for(int i=0;i<V[u].size();i++) {
		if(V[u][i] == p || fix[V[u][i]]) continue;
		half1(V[u][i],u,cur,mx,x,y);
	}
}
void centroid_decomp(int u){
	get_szs(u,0);
	int C = find_centroid(u,0,sz[u]);
	fix[C] = 1; 
	centroid=C;
//	if(C!=2) return;
//	cout<<C<<"++++"<<endl; 
	
	cnt.clear();
	ans_ = 0;
	for(int i=0;i<V[C].size();i++){
		if(fix[V[C][i]]) continue;
		half2(V[C][i],C,0,0,0,0);
		half1(V[C][i],C,c[C],max(0ll,c[C]),c[C] == 1,c[C]==-1);
	}// cout<<cnt[{2,0}]<<endl;
	reverse(V[C].begin(),V[C].end());
	cnt.clear();
	for(int i=0;i<V[C].size();i++){
		if(fix[V[C][i]]) continue;
		half2(V[C][i],C,0,0,0,0);
		half1(V[C][i],C,c[C],max(0ll,c[C]),c[C] == 1,c[C]==-1);
	} ans += ans_/2; //cout<<ans<<endl;
	for(int i=0;i<V[C].size();i++){
		if(fix[V[C][i]]) continue;
		centroid_decomp(V[C][i]);
	}
}
main(){
	cin>>n;
	for(int i=1;i<=n;i++){
		char ch;
		cin>>ch;
		if(ch=='(') c[i] = 1;
		else c[i] = -1;
	}
	for(int i=2;i<=n;i++){
		int u,v;
		cin>>u>>v;
		V[u].push_back(v);
		V[v].push_back(u);
	}
//	dfs(1,0);
	centroid_decomp(1);
	cout<<ans<<endl;
}

Compilation message (stderr)

zagrade.cpp: In function 'void get_szs(long long int, long long int)':
zagrade.cpp:12:15: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   12 |  for(int i=0;i<V[u].size();i++){
      |              ~^~~~~~~~~~~~
zagrade.cpp: In function 'long long int find_centroid(long long int, long long int, long long int)':
zagrade.cpp:19:15: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   19 |  for(int i=0;i<V[u].size();i++){
      |              ~^~~~~~~~~~~~
zagrade.cpp: In function 'void half2(long long int, long long int, long long int, long long int, long long int, long long int)':
zagrade.cpp:36:15: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |  for(int i=0;i<V[u].size();i++){
      |              ~^~~~~~~~~~~~
zagrade.cpp: In function 'void half1(long long int, long long int, long long int, long long int, long long int, long long int)':
zagrade.cpp:50:15: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   50 |  for(int i=0;i<V[u].size();i++) {
      |              ~^~~~~~~~~~~~
zagrade.cpp: In function 'void centroid_decomp(long long int)':
zagrade.cpp:65:15: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   65 |  for(int i=0;i<V[C].size();i++){
      |              ~^~~~~~~~~~~~
zagrade.cpp:72:15: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   72 |  for(int i=0;i<V[C].size();i++){
      |              ~^~~~~~~~~~~~
zagrade.cpp:77:15: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   77 |  for(int i=0;i<V[C].size();i++){
      |              ~^~~~~~~~~~~~
zagrade.cpp: At global scope:
zagrade.cpp:82:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   82 | main(){
      | ^~~~

• Subtask 1: 10 / 10
• Subtask 2: 0 / 30
• Subtask 3: 0 / 60