oj.uz

Submission #109755

# Submission time Handle Problem Language Result Execution time Memory
109755 2019-05-08T01:00:01 Z qkxwsm XOR (IZhO12_xor) C++14
100 / 100
 223 ms 24444 KB 
//clever
#pragma GCC optimize ("O3")
#pragma GCC target ("sse4")
#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/rope>

using namespace std;
using namespace __gnu_pbds;
using namespace __gnu_cxx;

random_device(rd);
mt19937 rng(rd());
const long long FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();

struct custom_hash
{
	template<class T>
	unsigned long long operator()(T v) const
	{
		unsigned long long x = v;
		x += FIXED_RANDOM;
		// x += 11400714819323198485ull;
		// x = (x ^ (x >> 30)) * 13787848793156543929ull;
		x = (x ^ (x >> 27)) * 10723151780598845931ull;
		return x ^ (x >> 31);
	}
};

template<class T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<class T, class U> using hash_table = gp_hash_table<T, U, custom_hash>;

template<class T>
T randomize(T mod)
{
	return (uniform_int_distribution<T>(0, mod - 1))(rng);
}
template<class T>
void readi(T &x)
{
	x = 0;
	bool negative = false;
	char c = ' ';
	while (c < '-')
	{
		c = getchar();
	}
	if (c == '-')
	{
		negative = true;
		c = getchar();
	}
	while (c >= '0')
	{
		x = x * 10 + (c - '0');
		c = getchar();
	}
	if (negative)
	{
		x = -x;
	}
}
template<class T>
void printi(T output)
{
	if (output == 0)
	{
		putchar('0');
		return;
	}
	if (output < 0)
	{
		putchar('-');
		output = -output;
	}
	int buf[20], n = 0;
	while(output)
	{
		buf[n] = ((output % 10));
		output /= 10;
		n++;
	}
	for (n--; n >= 0; n--)
	{
		putchar(buf[n] + '0');
	}
	return;
}
template<class T>
void ckmin(T &a, T b)
{
	a = min(a, b);
}
template<class T>
void ckmax(T &a, T b)
{
	a = max(a, b);
}
long long expo(long long a, long long e, long long mod)
{
	return ((e == 0) ? 1 : ((expo(a * a % mod, e >> 1, mod)) * ((e & 1) ? a : 1) % mod));
}
template<class T, class U>
void nmod(T &x, U mod)
{
	if (x >= mod) x -= mod;
}
template<class T>
T gcd(T a, T b)
{
	return (b ? gcd(b, a % b) : a);
}

#define y0 ___y0
#define y1 ___y1
#define MP make_pair
#define PB push_back
#define LB lower_bound
#define UB upper_bound
#define fi first
#define se second
#define DBG(x) cerr << #x << " = " << (x) << endl
#define SZ(x) ((int) ((x).size()))
#define FOR(i, a, b) for (auto i = (a); i < (b); i++)
#define FORD(i, a, b) for (auto i = (a) - 1; i >= (b); i--)
#define ALL(x) (x).begin(), (x).end()

const long double PI = 4.0 * atan(1.0);
const long double EPS = 1e-9;

#define MAGIC 347
#define SINF 10007
#define CO 1000007
#define INF 1000000007
#define BIG 1000000931
#define LARGE 1696969696967ll
#define GIANT 2564008813937411ll
#define LLINF 2696969696969696969ll
#define MAXN 250013

typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<ld, ld> pdd;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<ld> vd;
typedef vector<pii> vpi;
typedef vector<pll> vpl;
typedef vector<pdd> vpd;

int N, X, V;
int arr[MAXN];
int ch[2][MAXN * 32];
int late[MAXN * 32];
pii ans;

void ins(int x, int id)
{
	int node = 0;
	FORD(i, 31, 0)
	{
		bool c = (x & (1 << i));
		if (!ch[c][node])
		{
			V++;
			ch[c][node] = V;
		}
		node = ch[c][node];
		ckmax(late[node], id);
		// cerr << node << ' ' << id << endl;
	}
}
int ask(int v)
{
	int res = 0, node = 0;
	FORD(i, 31, 0)
	{
		bool want = (X & (1 << i)), cur = (v & (1 << i));
		if (!want)
		{
			ckmax(res, late[ch[!cur][node]]);
			// cerr << node << ' ' << late[ch[!cur][node]] << endl;
		}
		node = ch[cur ^ want][node];
		if (!node) break;
	}
	if (node) ckmax(res, late[node]);
	return res;
}

int32_t main()
{
	ios_base::sync_with_stdio(0); cin.tie(0);
	// cout << fixed << setprecision(10);
	// cerr << fixed << setprecision(10);
	// if (fopen("file.in", "r"))
	// {
	// 	freopen ("file.in", "r", stdin);
	// 	freopen ("file.out", "w", stdout);
	// }
	cin >> N >> X;
	FOR(i, 1, N + 1)
	{
		cin >> arr[i]; arr[i] ^= arr[i - 1];
	}
	// FOR(i, 0, N + 1) DBG(arr[i]);
	FORD(i, N + 1, 0)
	{
		int rt = ask(arr[i]);
		if (rt - i >= ans.fi)
		{
			// cerr << i << " -> " << (rt - 1) << endl;
			ans = {rt - i, i};
			// cerr << ans.fi << ',' << ans.se << endl;
		}
		ins(arr[i], i);
	}
	cout << ans.se + 1 << ' ' << ans.fi << '\n';
	// cerr << "time elapsed = " << (clock() / (CLOCKS_PER_SEC / 1000)) << " ms" << endl;
	return 0;
}
/* READ READ READ
* int overflow, maxn too small, special cases (n=1?, two distinct?), cin.tie() interactive
* reread the problem, try small cases
* note down possible sources of error as you go
* do smth instead of nothing
*/

Subtask #1
100.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 428 KB Output is correct
2 Correct 2 ms 384 KB Output is correct
3 Correct 2 ms 384 KB Output is correct
4 Correct 3 ms 512 KB Output is correct
5 Correct 11 ms 1024 KB Output is correct
6 Correct 16 ms 1024 KB Output is correct
7 Correct 13 ms 1152 KB Output is correct
8 Correct 13 ms 1152 KB Output is correct
9 Correct 74 ms 10744 KB Output is correct
10 Correct 59 ms 11512 KB Output is correct
11 Correct 61 ms 11512 KB Output is correct
12 Correct 63 ms 11428 KB Output is correct
13 Correct 57 ms 11512 KB Output is correct
14 Correct 57 ms 11512 KB Output is correct
15 Correct 58 ms 11512 KB Output is correct
16 Correct 62 ms 11512 KB Output is correct
17 Correct 166 ms 24336 KB Output is correct
18 Correct 158 ms 24388 KB Output is correct
19 Correct 164 ms 24444 KB Output is correct
20 Correct 223 ms 24336 KB Output is correct