Submission #250655

# Submission time Handle Problem Language Result Execution time Memory
250655 2020-07-18T15:13:59 Z srvlt XOR (IZhO12_xor) C++14
100 / 100
228 ms 46760 KB
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
#define ll long long
#define ld long double
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define SZ(x) (int)(x).size()
template <typename T> using ord_set = tree <T, null_type, less <T>, rb_tree_tag, tree_order_statistics_node_update>;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const int n0 = 250007, k0 = 30;
int n, k, a[n0], T[2][n0 * k0], sz;
int mn[n0 * k0];

void add(int pos) {
	int v = 0, x = a[pos];
	for (int i = k0 - 1; i >= 0; i--) {
		if (!T[x >> i & 1][v])
			T[x >> i & 1][v] = ++sz;
		v = T[x >> i & 1][v];
	}
	mn[v] = min(mn[v], pos);
}

void dfs(int v) {
	for (int i = 0; i < 2; i++) {
		int to = T[i][v];
		if (to) {
			dfs(to);
			mn[v] = min(mn[v], mn[to]);
		}
	}
}

int X;

int get(int v, int cur, int x, int d) {
	if ((cur ^ x) >= k) return mn[v];
	if ((cur ^ x) + (1 << (d + 1)) - 1 < k) return n0;
	int res = n0;
	for (int i = 0; i < 2; i++) {
		int to = T[i][v];
		int bit = (i) ? (1 << d) : 0;
		int bit2 = X & (1 << d); 
		if (to) res = min(res, get(to, cur ^ bit, x ^ bit2, d - 1));
	}
	return res;
}

int main() {
	ios_base::sync_with_stdio(false), cin.tie(NULL);
	#ifdef LOCAL
		freopen("input.txt", "r", stdin);
	#endif
	
	memset(& mn, 0x3f, sizeof(mn));
	cin >> n >> k;
	add(0);
	for (int i = 1; i <= n; i++) {
		cin >> a[i];
		a[i] ^= a[i - 1];
		add(i);
	}
	dfs(0);
	int res = 0, ind = -1;
	for (int i = 1; i <= n; i++) {
		X = a[i];
		int l = get(0, 0, 0, k0 - 1);
		if (l < i && i - l > res)
			res = i - l, ind = i;
	}
	cout << ind - res + 1 << ' ' << res;
}
# Verdict Execution time Memory Grader output
1 Correct 16 ms 29696 KB Output is correct
2 Correct 15 ms 29696 KB Output is correct
3 Correct 15 ms 29696 KB Output is correct
4 Correct 17 ms 29824 KB Output is correct
5 Correct 23 ms 30208 KB Output is correct
6 Correct 25 ms 30336 KB Output is correct
7 Correct 28 ms 30336 KB Output is correct
8 Correct 27 ms 30416 KB Output is correct
9 Correct 85 ms 37496 KB Output is correct
10 Correct 88 ms 37496 KB Output is correct
11 Correct 77 ms 37624 KB Output is correct
12 Correct 114 ms 37496 KB Output is correct
13 Correct 89 ms 37496 KB Output is correct
14 Correct 87 ms 37496 KB Output is correct
15 Correct 90 ms 37524 KB Output is correct
16 Correct 78 ms 37496 KB Output is correct
17 Correct 212 ms 46712 KB Output is correct
18 Correct 206 ms 46760 KB Output is correct
19 Correct 216 ms 46712 KB Output is correct
20 Correct 228 ms 46712 KB Output is correct