Submission #440873

#	Time	Username	Problem	Language	Result	Execution time	Memory
440873		codebuster_10	XOR (IZhO12_xor)	C++17	0 / 100	1 ms	204 KiB

xor

#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 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); 
  // remove this when size of input is not fixed.
  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);
  }
}


/*********************************************Look Below******************************************************************/








































const int INF = int(1e9) + 5, LOG = 31;


template<const int ALPHABET>
struct prefix_tree {
	
	struct trie_node {
  	int link[ALPHABET];
    int value;
 
    trie_node() {
      memset(link, -1, sizeof(link));
      value = INF;
    }
	};
	
	vector<trie_node> trie;
	
	prefix_tree(){
		trie.emplace_back();
	}
	
	void create_node(int parent, int c) {
    trie.emplace_back();
	}
	
	int get_or_create_node(int current, int c) {
    if (trie[current].link[c] < 0) {
      trie[current].link[c] = trie.size();
      create_node(current, c);
    }
 
    return trie[current].link[c];
	}
 
	int insert_str(const int & x,const int & i) {
		int current = 0;
    for(int j = LOG - 1; ~j; --j){
    	int c = (x >> i & 1);
      current = get_or_create_node(current, c);
      ckmin(trie[current].value,i);
 		}
    return current;
	}
	
	int query(const int & v, const int & x){
		int ans = INF;
		int current = 0;
		for(int j = LOG - 1; ~j; --j){
			int cv = (v >> j & 1), cx = (x >> j & 1);
			
			if(cx == 0){
				int need = (cv^1);
				if(trie[current].link[need] > 0){
					ckmin(ans,trie[trie[current].link[need]].value);
				}
			}
			
			int to = cv ^ cx;
			if(trie[current].link[to] < 0) break;
			current = trie[current].link[to];
		}
		
		return ans;
	}
};

prefix_tree<2> trie;

signed main(){
  setIO();
	int n,x; rd(n,x);
	vt<int> a(n+1,0);
	f(i,1,n+1) rd(a[i]);
	
	f(i,1,n+1) a[i] ^= a[i-1];
	
	f(i,0,n+1) trie.insert_str(a[i],i);
	
	int len = 0, st = -1;
	
	f(i,1,n+1){
		int tmp = trie.query(a[i],x);
		if(ckmax(len,i-tmp)){
			st = i - len + 1;
		}
	}
	
	cout << st << " " << len << endl;
	
}

Compilation message (stderr)

xor.cpp: In function 'void setIO(std::string)':
xor.cpp:82:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   82 |    freopen((s+".in").c_str(),"r",stdin);
      |    ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
xor.cpp:83:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   83 |    freopen((s+".out").c_str(),"w",stdout);
      |    ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 100