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Submission #883487

# Submission time Handle Problem Language Result Execution time Memory
883487 2023-12-05T10:56:02 Z NintsiChkhaidze XOR (IZhO12_xor) C++17
100 / 100
 144 ms 39452 KB 
#include <bits/stdc++.h>
#define pb push_back
#define s second
#define f first
#define left (h<<1),l,(l + r)/2
#define right ((h<<1)|1),(l + r)/2 + 1,r
#define pii pair<int,int>
#define ll long long
// #define int ll
using namespace std;

const int N = 250000 + 5;

int a[N],p[N],tot = 1,child[N * 33][4],val[N * 33];

void upd(int k,int i){
	int cur = 1;
	for (int j = 30; j >= 0; j--){
		int b = (k & (1<<j)) > 0;
		if (!child[cur][b]){
			child[cur][b] = ++tot;
		}
		cur = child[cur][b];
		val[cur] = max(val[cur],i);
	}	
}

int find(int i,int mask,int lim){
	// ... == mask ^ p[i - 1]
	
	mask ^= p[i - 1];
	int cur = 1;

	for (int j = 30; j >= lim; j--){
		int b = (mask & (1<<j)) > 0;
		if (!child[cur][b]) return -1;
		cur = child[cur][b];
	}

	return val[cur] - i + 1;
}

signed main (){
    ios_base::sync_with_stdio(0),cin.tie(NULL),cout.tie(NULL);
	
	// freopen("game.in", "r", stdin);
	// freopen("game.out", "w", stdout);

	int n,x;
	cin>>n>>x;

	for (int i = 1; i <= n; i++){
		cin >> a[i];
		p[i] = p[i - 1] ^ a[i];
	}

	int ans1 = 0,ans2 = 0;
	for (int i = n; i >= 1; i--){
		upd(p[i],i);
		int res = find(i,x,0);
		if (res >= ans2) ans1 = i,ans2 = res;  

		int mask = 0;
		for (int j = 30; j >= 0; j--){
			if (!(x & (1<<j))){
				int res = find(i,(mask ^ (1<<j)),j);
				if (res >= ans2) ans1=i,ans2=res;  
			}
			mask ^= (x & (1<<j));
		}
	}

	cout<<ans1<<" "<<ans2;
}

Subtask #1
100.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 1 ms 604 KB Output is correct
5 Correct 6 ms 1516 KB Output is correct
6 Correct 9 ms 1628 KB Output is correct
7 Correct 8 ms 1628 KB Output is correct
8 Correct 10 ms 1880 KB Output is correct
9 Correct 52 ms 18832 KB Output is correct
10 Correct 39 ms 18512 KB Output is correct
11 Correct 39 ms 18528 KB Output is correct
12 Correct 37 ms 18388 KB Output is correct
13 Correct 38 ms 18516 KB Output is correct
14 Correct 38 ms 18436 KB Output is correct
15 Correct 53 ms 18376 KB Output is correct
16 Correct 39 ms 18512 KB Output is correct
17 Correct 144 ms 39408 KB Output is correct
18 Correct 118 ms 39452 KB Output is correct
19 Correct 126 ms 39248 KB Output is correct
20 Correct 111 ms 39352 KB Output is correct