Submission #486165

#	Time	Username	Problem	Language	Result	Execution time	Memory
486165		acm	XOR (IZhO12_xor)	C++14	100 / 100	118 ms	25284 KiB

xor

#ifdef ONLINE_JUDGE
#pragma GCC optimize("Ofast,no-stack-protector,unroll-loops,fast-math,O3")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#endif
#include <bits/stdc++.h>
#define speed                   \
  ios_base::sync_with_stdio(0); \
  cin.tie(0);                   \
  cout.tie(0);
#define precision     \
  cout.precision(30); \
  cerr.precision(10);
#define ll long long
#define ld long double
#define pb(x) push_back(x)
#define sz(x) (int)x.size()
#define mp(x, y) make_pair(x, y)
#define all(x) x.begin(), x.end()
#define pc(x) __builtin_popcount(x)
#define pcll(x) __builtin_popcountll(x)
#define F first
#define S second
using namespace std;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
void ioi(string name) {
  freopen((name + ".in").c_str(), "r", stdin);
  freopen((name + ".out").c_str(), "w", stdout);
}
int n, k, P, res, ser, a[250005], b[250005], go[30 * 250005][2], g[60 * 250005];
void add(int x) {
  int v = 0;
  for (int i = 30; i >= 0; i--) {
    int h = !!((1 << i) & b[x]);
    if (!go[v][h]) go[v][h] = ++P;
    v = go[v][h];
    g[v] = x;
  }
}
int get(int x) {
  int v = 0, z = 0;
  for (int i = 30; i >= 0; i--) {
    int h = !!((1 << i) & x);
    int d = !!((1 << i) & k);
    if (!d && go[v][!h]) z = max(z, g[go[v][!h]]);
    v = go[v][h ^ d];
    if (!v) break;
  }
  return max(z, g[v]);
}
int main() {
  speed;
  precision;
  // code
  cin >> n >> k;
  for (int i = 1; i <= n; i++) cin >> a[i], b[i] = b[i - 1] ^ a[i];
  for (int i = 0; i <= n; i++) add(i);
  for (int i = 0; i < n; i++) {
    int x = get(b[i]);
    if (k <= (b[i] ^ b[x]) && x - i > ser) {
      ser = x - i;
      res = i + 1;
    }
  }
  cout << res << " " << ser;
  // endl
#ifndef ONLINE_JUDGE
  cerr << "\nTime elapsed: " << 1.0 * clock() / CLOCKS_PER_SEC << " s.\n";
#endif
  return 0;
}

Compilation message (stderr)

xor.cpp: In function 'void ioi(std::string)':
xor.cpp:26:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   26 |   freopen((name + ".in").c_str(), "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
xor.cpp:27:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   27 |   freopen((name + ".out").c_str(), "w", stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 100 / 100