Submission #1101688

#	Time	Username	Problem	Language	Result	Execution time	Memory
1101688		thefless	XOR (IZhO12_xor)	C++17	100 / 100	95 ms	120768 KiB

xor

#include<bits/stdc++.h>
using namespace std;
#define MASK(i) (1LL << (i))
#define BIT(x, i) (((x) >> (i)) & 1)
#define Times (1.0 * clock() / CLOCKS_PER_SEC)
#define fi first
#define base 31
#define sz(x) (int)(x).size()
#define se second
#define ll long long
#define mp make_pair
#define pb push_back
#define pii pair<int, int>
#define all(x) (x).begin(), (x).end()

#define file(name)  if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); freopen(name".bug", "w", stderr); }
#define task "name" 
#define tsk "" 

const int oo = 1e9 + 7;
const ll loo = (ll)1e18 + 7;
const int MOD = 1e9 + 7;
const int MOD2 = 1e9 + 696969;
const int N = 250000 + 3;
const int BASE = 10;

template <typename T1, typename T2> bool minimize(T1 &a, T2 b){if (a > b) {a = b; return true;} return false;}
template <typename T1, typename T2> bool maximize(T1 &a, T2 b){if (a < b) {a = b; return true;} return false;}

int n , x;
int a[N];
struct TRIE{
    struct NODE{
        int cnt, idx;
        int child[2];
        NODE(){cnt = child[0] = child[1] = 0;idx = oo;}
    }t[N * 30];
    int cnt;
    void add(int s, int vt){
        int root = 0;
        for(int i = 30 ; i >= 0 ; i--){
            int id = BIT(s , i);
            if(!t[root].child[id]) t[root].child[id] = ++cnt;
            root = t[root].child[id];
            t[root].cnt++;
            minimize(t[root].idx , vt);
        }
    }
    int dfs(int root , int s , int dept){
        if(root == 0 && dept != 30) return oo;
        if(dept < 0) return t[root].idx;
        int l = t[root].child[0];
        int r = t[root].child[1];
        if(BIT(s , dept)) swap(l , r);
        if(BIT(x , dept)){
            int res = dfs(r , s , dept - 1);
            return res;
        }
        int res = dfs(l , s , dept - 1);
        return min(t[r].idx , res);
    }
}trie;
void Solve(){
    cin >> n >> x;
    for(int i = 1 ; i <= n ; i++) cin >> a[i];
    trie.add(0 , 0);
    int pre = 0 , siz = 0 , st = 0;
    for(int i = 1 ; i <= n ; i++){
        pre ^= a[i];
        int w = trie.dfs(0 , pre , 30);
        if(w != oo){
            if(maximize(siz , i - w)) st = w + 1;
        }
        trie.add(pre , i);
    }
    cout << st << ' ' << siz;
}

int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0);
    file(task);
    file(tsk);
    int T = 1;
    // cin >> T;
    while(T--)
    {
        Solve();
    }
    cerr << "Time elapsed: " << Times << " s.\n";
    return 0;
}
// author: thefless

Compilation message (stderr)

xor.cpp: In function 'int main()':
xor.cpp:16:58: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 | #define file(name)  if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); freopen(name".bug", "w", stderr); }
      |                                                   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
xor.cpp:82:5: note: in expansion of macro 'file'
   82 |     file(task);
      |     ^~~~
xor.cpp:16:91: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 | #define file(name)  if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); freopen(name".bug", "w", stderr); }
      |                                                                                    ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
xor.cpp:82:5: note: in expansion of macro 'file'
   82 |     file(task);
      |     ^~~~
xor.cpp:16:125: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 | #define file(name)  if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); freopen(name".bug", "w", stderr); }
      |                                                                                                                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
xor.cpp:82:5: note: in expansion of macro 'file'
   82 |     file(task);
      |     ^~~~
xor.cpp:16:58: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 | #define file(name)  if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); freopen(name".bug", "w", stderr); }
      |                                                   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
xor.cpp:83:5: note: in expansion of macro 'file'
   83 |     file(tsk);
      |     ^~~~
xor.cpp:16:91: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 | #define file(name)  if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); freopen(name".bug", "w", stderr); }
      |                                                                                    ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
xor.cpp:83:5: note: in expansion of macro 'file'
   83 |     file(tsk);
      |     ^~~~
xor.cpp:16:125: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 | #define file(name)  if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); freopen(name".bug", "w", stderr); }
      |                                                                                                                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
xor.cpp:83:5: note: in expansion of macro 'file'
   83 |     file(tsk);
      |     ^~~~

• Subtask 1: 100 / 100