Submission #1098052

#	Time	Username	Problem	Language	Result	Execution time	Memory
1098052		anhthi	XOR (IZhO12_xor)	C++14	0 / 100	1 ms	344 KiB

xor

#include <bits/stdc++.h>
 
using namespace std;
 
#define fi first
#define se second
#define ll long long
#define mp(x, y) make_pair(x, y)
#define sz(v) ((int) (v).size())
#define all(v) (v).begin(), (v).end()
#define MASK(i) (1LL << (i))
#define BIT(x, y) (((x) >> (y)) & 1)
#define pb push_back
#define heap priority_queue
#define max_rng *max_element
#define min_rng *min_element
#define rep(i, n) for(int i = 1, _n = (n); i <= _n; ++i)
#define forn(i, a, b) for(int i = (a), _b = (b); i <= _b; ++i)
#define ford(i, a, b) for(int i = (a), _b = (b); i >= _b; --i)

 
template <class X, class Y>
    inline bool maximize(X &x, Y y) {
        return (x < y ? x = y, true : false);
    }
 
template <class X, class Y>
    inline bool minimize(X &x, Y y) {
        return (x > y ? x = y, true : false);
    }
 
template <class X>
    inline void compress(vector<X> &a) {
        sort(all(a));
        a.resize(unique(all(a)) - a.begin());
    }
 
int ctz(ll x) { return __builtin_ctzll(x); }
int lg(ll x) { return 63 - __builtin_clzll(x); }
int popcount(ll x) { return __builtin_popcount(x); }
 
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rand(ll l, ll r) {
    return l + abs((ll) rng()) % (r - l + 1);
}
 
const ll oo = (ll) 1e18 + 5;
const int inf = (ll) 1e9 + 7, mod = (ll) 1e9 + 7;
 
const int N = 3e5 + 5, LOG = 30;
 
void add(int &x, int y) { x += y; if (x >= mod) x -= mod; }
void sub(int &x, int y) { x -= y; if (x < 0) x += mod; }

int n, x;
int a[N], pf[N];

struct triee {

    struct node {
        int min_index;
        int childs[2];
        node() {
            min_index = inf;
            forn(i, 0, 1) childs[i] = -1;
        }
    };
    vector<node> tree;

    triee() { create(); }
    void create() { tree.pb(node()); }

    void addInt(int num, int index) {
        int p = 0;
        ford(i, LOG, 0) {
            int bit = BIT(num, i);
            if (tree[p].childs[bit] == -1) {
                create();
                tree[p].childs[bit] = sz(tree) - 1;
            }
            p = tree[p].childs[bit];
            minimize(tree[p].min_index, index);
        }
        return;
    }

    int figure(int p, int h, int value) {
        if (h == -1) return inf;
        int bit = BIT(value, h);
        int lc = tree[p].childs[bit ^ 0];
        int rc = tree[p].childs[bit ^ 1];
        // cout << p << ' ' << h << ' ' << value << ' ' << lc << ' ' << rc << " \n";
        int ans = inf;
        if (rc != -1 && MASK(h) >= x) {
            minimize(ans, tree[rc].min_index);
        }
        if (lc != -1) minimize(ans, figure(lc, h - 1, value));
        return ans;
    }

};

int main(void) {
 
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    
    cin >> n >> x;
    rep(i, n) cin >> a[i];
    rep(i, n) pf[i] = pf[i-1] ^ a[i];

    triee trie;
    trie.addInt(0, 0);

    // cout << (pf[8]) << '\n';
    int pos = -1, len = -1;
    rep(i, n) {
        int pre = trie.figure(0, LOG, pf[i]);
        // cout << i << ' ' << pre << '\n';
        if (maximize(len, i - pre)) pos = pre + 1;
        trie.addInt(pf[i], i);
        // cout << "\n\n";
    }

    cout << pos << ' ' << len;

    return 0;
}

• Subtask 1: 0 / 100