Submission #428401

#	Time	Username	Problem	Language	Result	Execution time	Memory
428401		codebuster_10	Synchronization (JOI13_synchronization)	C++17	100 / 100	864 ms	35488 KiB

synchronization

#include <bits/stdc++.h>
 
using namespace std ;
 
#define int int64_t //be careful about this 
#define endl "\n"
#define f(i,a,b) for(int i=int(a);i<int(b);++i)
 
#define pr pair
#define ar array
#define fr first
#define sc second
#define vt vector
#define pb push_back
#define eb emplace_back
#define LB lower_bound  
#define UB upper_bound
#define PQ priority_queue
 
#define sz(x) ((int)(x).size())
#define all(a) (a).begin(),(a).end()
#define allr(a) (a).rbegin(),(a).rend()
#define mem(a,b) memset(a, b, sizeof(a))
 
template<class A> void rd(vt<A>& v);
template<class T> void rd(T& x){ cin >> x; }
template<class H, class... T> void rd(H& h, T&... t) { rd(h) ; rd(t...) ;}
template<class A> void rd(vt<A>& x) { for(auto& a : x) rd(a) ;}
 
template<class T> bool ckmin(T& a, const T& b) { return b < a ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) { return a < b ? a = b, 1 : 0; }
 
template<typename T>
void __p(T a) {
  cout<<a; 
}
template<typename T, typename F>
void __p(pair<T, F> a) {
  cout<<"{";
  __p(a.first);
  cout<<",";
  __p(a.second);
  cout<<"}\n"; 
}
template<typename T>
void __p(std::vector<T> a) {
  cout<<"{";
  for(auto it=a.begin(); it<a.end(); it++)
    __p(*it),cout<<",}\n"[it+1==a.end()]; 
}
template<typename T, typename ...Arg>
void __p(T a1, Arg ...a) {
  __p(a1);
  __p(a...);
}
template<typename Arg1>
void __f(const char *name, Arg1 &&arg1) {
  cout<<name<<" : ";
  __p(arg1);
  cout<<endl;
}
template<typename Arg1, typename ... Args>
void __f(const char *names, Arg1 &&arg1, Args &&... args) {
  int bracket=0,i=0;
  for(;; i++)
    if(names[i]==','&&bracket==0)
      break;
    else if(names[i]=='(')
      bracket++;
    else if(names[i]==')')
      bracket--;
  const char *comma=names+i;
  cout.write(names,comma-names)<<" : ";
  __p(arg1);
  cout<<" | ";
  __f(comma+1,args...);
}
 
void setIO(string s = "") {
  ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); 
  cin.exceptions(cin.failbit); 
	cout.precision(15);	cout << fixed;
  if(sz(s)){
  	freopen((s+".in").c_str(),"r",stdin);
  	freopen((s+".out").c_str(),"w",stdout);
  }
}
 
 
 
 
 
template <class T, int ...Ns> struct BIT {
	T val = 0; void upd(T v) { val += v; }
	T query() { return val; }
};
template <class T, int N, int... Ns> struct BIT<T, N, Ns...> {
	BIT<T,Ns...> bit[N+1];
	template<typename... Args> void upd(int pos, Args... args) { assert(pos > 0);
		for (; pos<=N; pos+=pos&-pos) bit[pos].upd(args...); }
	template<typename... Args> T sum(int r, Args... args) {
		T res=0; for (;r;r-=r&-r) res += bit[r].query(args...); 
		return res; }
	template<typename... Args> T query(int l, int r, Args... 
		args) { return sum(r,args...)-sum(l-1,args...); }
}; 
 
 
 
const int MAX_N = 1e5 + 7, LOG = 20;
BIT<int,MAX_N> bit;
vector<int> g[MAX_N];
int st[MAX_N], en[MAX_N], up[MAX_N][LOG], timer, ans[MAX_N], edge[MAX_N], active[MAX_N];
 
 
void dfs(int i,int p){
  st[i] = timer++;
  up[i][0] = p;
  for(int j = 1; j < LOG; ++j){
    up[i][j] = up[up[i][j-1]][j-1];
  } 
  for(auto j : g[i]) if(j != p) {
    dfs(j,i);
  }
  en[i] = timer - 1 ;
}
 
 
signed main(){
	int n,m,q; rd(n,m,q);
	vt<ar<int,2>> edges;
	f(_,0,n-1){
		int u,v; rd(u,v); --u,--v;
		edges.pb({u,v});
		g[u].pb(v);
		g[v].pb(u);
	}
	dfs(0,0);
	
	fill(ans, ans + n, 1);
	fill(edge, edge + n, 0);
	fill(active, active + n, 0);
	
	for(auto& [u,v] : edges){
		if(st[v] > st[u]) swap(u,v);
	}
	
	auto add = [&](int x,int v) -> void {
		// add value in edge whose lower node is x.
		bit.upd(st[x],v);
		bit.upd(en[x]+1,-v);
		return;
	};
	
	auto get = [&](int x) -> int {
		// get sum of edges whose lower node is x.
		if(x == 0) return int(0);
		return bit.query(1,st[x]);
	};
	
	auto root = [&](int x) -> int {
		for(int i = LOG - 1; i >= 0; --i){
			int j = up[x][i];
			if(get(x) - get(j) == (1<<i)){
				x = j;
			}
		}
		return x;
	};
	
 
	f(_,0,m){
		int d; rd(d); --d;
		auto [u,v] = edges[d];// here u is child and v is parent.
		if(active[d]){
			edge[u] = ans[u] = ans[root(v)];
			add(u,-1);
		}else{
			int tmp = ans[root(u)] + ans[root(v)] - edge[u];
			edge[u] = tmp;
			add(u,1);
			ans[root(v)] = tmp;
		}
		active[d] ^= 1;
	}
	
	while(q--){
		int c; rd(c); --c;
		cout << ans[root(c)] << endl;
	}
	
}
 

Compilation message (stderr)

synchronization.cpp: In function 'void setIO(std::string)':
synchronization.cpp:84:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   84 |    freopen((s+".in").c_str(),"r",stdin);
      |    ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
synchronization.cpp:85:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   85 |    freopen((s+".out").c_str(),"w",stdout);
      |    ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 10 / 10
• Subtask 4: 20 / 20
• Subtask 5: 40 / 40