Submission #1134247

#	Time	Username	Problem	Language	Result	Execution time	Memory
1134247		steveonalex	XOR (IZhO12_xor)	C++20	100 / 100	67 ms	22344 KiB

xor

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;

#define MASK(i) (1LL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()

ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}

ll gcd(ll a, ll b){return __gcd(a, b);}
ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ll mask){return __builtin_popcountll(mask);}
int ctz(ll mask){return __builtin_ctzll(mask);}
int logOf(ll mask){return __lg(mask);}

mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}

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

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

template <class T>
    void printArr(T& container, string separator = " ", string finish = "\n"){
        for(auto item: container) cout << item << separator;
        cout << finish;
    }


template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }

const int INF = 1e9 + 69;

struct Trie{
    struct Node{
        int mi;
        int child[2];
        Node(){mi = INF; memset(child, -1, sizeof child);}
    };

    vector<Node> a;

    Trie(int n){
        a.reserve(n);
        a.push_back(Node());
    }

    void add_child(int &x){
        x = a.size();
        a.push_back(Node());
    }

    void add(int x, int i){
        int id=  0;
        minimize(a[id].mi, i);
        for(int j = 29; j >= 0; --j) {
            int digit = GETBIT(x, j);
            if (a[id].child[digit] == -1) add_child(a[id].child[digit]);
            id = a[id].child[digit];
            minimize(a[id].mi, i);
        }
    }

    int get_mi_xor(int x, int y){
        int id = 0;
        int ans = INF;
        bool escaped_early = false;
        for(int j = 29;j >= 0; --j){
            int digit = GETBIT(x, j);
            if (GETBIT(y, j)){
                int v = a[id].child[digit ^ 1];
                if (v == -1) {
                    escaped_early = true;
                    break;
                }
                id = v;
            }  
            else{
                int u = a[id].child[digit], v = a[id].child[digit ^ 1];
                if (v != -1){
                    minimize(ans, a[v].mi);
                }
                if (u == -1) {
                    escaped_early = true;
                    break;
                }
                id = u;
            }
        }
        if (!escaped_early) minimize(ans, a[id].mi);
        return ans;
    }
};

void solve(){
    int n, x; cin >> n >> x;
    vector<int> a(n+1);
    for(int i = 1; i <= n; ++i){
        cin >> a[i];
        a[i] ^= a[i-1];
    }

    Trie tri(5e6);
    int ans = 0, pos = 0;
    for(int i = 0; i <= n; ++i){
        tri.add(a[i], i);
        if (maximize(ans, i - tri.get_mi_xor(a[i], x))){
            pos = i - ans + 1;
        }
    }
    cout << pos << " " << ans << "\n";
}

int main(void){
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    clock_t start = clock();

    solve();

    cerr << "Time elapsed: " << clock() - start << "ms!\n";
    return 0;
}

• Subtask 1: 100 / 100