Submission #531370

#	Time	Username	Problem	Language	Result	Execution time	Memory
531370		fcw	XOR (IZhO12_xor)	C++17	100 / 100	201 ms	32436 KiB

xor

#include <bits/stdc++.h>
#define st first
#define nd second
using lint = int64_t;
constexpr int mod = int(1e9) + 7;
constexpr int inf = 0x3f3f3f3f;
constexpr int ninf = 0xcfcfcfcf;
constexpr lint linf = 0x3f3f3f3f3f3f3f3f;
const long double pi = acosl(-1.0);
// Returns -1 if a < b, 0 if a = b and 1 if a > b.
int cmp_double(double a, double b = 0, double eps = 1e-9) {
	return a + eps > b ? b + eps > a ? 0 : 1 : -1;
}
using namespace std;

const int K = 31;

int main() {
	cin.tie(nullptr)->sync_with_stdio(false);
	vector<array<int, 2>>trie(1, {-1, -1});
	vector<int>id(1, -1);
	int n, x;
	cin>>n>>x;
	vector<int>v(n+1);
	int mx = -1, ind = -1;
	int cnt = 0;
	for(int i=0;i<=n;i++){
		if(i) cin>>v[i];
		cnt ^= v[i];
		if(i){
			int cur = 0, mask = 0;
			for(int a=K;a>=0;a--){
				int b = cnt>>a&1;
				if(trie[cur][!b] == -1){
					cur = trie[cur][b];
				}
				else{
					mask |= (1<<a);
					cur = trie[cur][!b];
					if(mask >= x){
						//cout<<i+1<<" "<<mask<<" "<<id[cur]<<" "<<a<<"\n";
						if(mx < i+1 - id[cur]){
							mx = i+1 - id[cur];
							ind = id[cur];
						}
					}
				}
			}
		}
		int cur = 0;
		for(int a=K;a>=0;a--){
			int b = cnt>>a&1;
			if(trie[cur][b] == -1){
				trie[cur][b] = (int)trie.size();
				trie.push_back({-1, -1});
				id.push_back(i+1);
			}
			cur = trie[cur][b];
		}
	}
	cout<<ind<<" "<<mx<<"\n";

	return 0;
}
/*
[  ]Leu o problema certo???
[  ]Ver se precisa de long long
[  ]Viu o limite dos fors (é n? é m?)
[  ]Tamanho do vetor, será que é 2e5 em vez de 1e5??
[  ]Testar sample
[  ]Testar casos de  borda
[  ]1LL no 1LL << i
[  ]Testar mod (é 1e9+7, mesmo?, será que o mod não ficou negativo?)
*/

• Subtask 1: 100 / 100