Submission #917268

#	Time	Username	Problem	Language	Result	Execution time	Memory
917268		Whisper	XOR (IZhO12_xor)	C++17	100 / 100	139 ms	62948 KiB

xor

#include <bits/stdc++.h>

using namespace std;
using ll = long long;
using ld = long double;
using T = tuple<ll, ll, ll>;

#define int long long
#define Base 41
#define sz(a) (int)a.size()
#define FOR(i, a, b) for ( int i = a ; i <= b ; i++ )
#define FORD(i, a, b) for (int i = b; i >= a; i --)
#define REP(i, n) for (int i = 0; i < n; ++i)
#define REPD(i, n) for (int i = n - 1; i >= 0; --i)
#define all(x) x.begin() , x.end()
#define pii pair<int , int>
#define fi first
#define se second
#define Lg(x) 31 - __builtin_clz(x)

#define MASK(i) (1LL << (i))
#define BIT(x, i) (((x) >> (i)) & 1)

constexpr ll LINF = (1ll << 60);
constexpr int INF = (1ll << 30);
constexpr int MAX = 3e5 + 5;
constexpr int Mod = 1e9 + 7;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

void setupIO(){
    #define name "Whisper"
    //Phu Trong from Nguyen Tat Thanh High School for gifted student
    srand(time(NULL));
    cin.tie(nullptr)->sync_with_stdio(false); cout.tie(nullptr);
    //freopen(name".inp", "r", stdin);
    //freopen(name".out", "w", stdout);
    cout << fixed << setprecision(10);
}

template <class X, class Y>
    bool minimize(X &x, const Y &y){
        X eps = 1e-9;
        if (x > y + eps) {x = y; return 1;}
        return 0;
    }

template <class X, class Y>
    bool maximize(X &x, const Y &y){
        X eps = 1e-9;
        if (x + eps < y) {x = y; return 1;}
        return 0;
    }
int N, X;
int a[MAX];

struct Node{
    Node *child[2];
    int id;
    Node(){
        child[0] = child[1] = nullptr;
        id = -1;
    }
};

Node *root = new Node();

int f[MAX];
void Add(int x){
    Node *p = root;
    int c = f[x];
    REPD(i, 31){
        int nxt = BIT(c, i);
        if (p -> child[nxt] == nullptr) p -> child[nxt] = new Node();
        p = p -> child[nxt];
        if (p -> id == -1) p -> id = x;
    }
    if (p -> id == -1) p -> id = x;
}
int Ask(int x){
    int ans = INF;
    Node *p = root;
    REPD(i, 31){
        int nxt = BIT(x, i);
        int nxtX = BIT(X, i);
        if (nxtX){
            if (p -> child[nxt ^ 1] == nullptr) return ans;
            p = p -> child[nxt ^ 1];
        }
        else{
            if (p -> child[nxt ^ 1] != nullptr){
                ans = min(ans, p -> child[nxt ^ 1] -> id);
            }
            if(p -> child[nxt] != nullptr){

                p = p -> child[nxt];
            }
            else return ans;
        }
    }
    ans = min(ans, p -> id);
    assert(ans != -1);
    return ans;
}
void Whisper(){
    cin >> N >> X;
    for (int i = 1; i <= N; ++i) cin >> a[i];
    Add(0);
    for (int i = 1; i <= N; ++i){
        f[i] = f[i - 1] ^ a[i];
    }
    int idx = -1, len = 0;
    for (int i = 1; i <= N; ++i){
        int p = Ask(f[i]);
        Add(i);
        if (p > 1e9) continue;
        ++p;
        if (maximize(len, i - p + 1)){
            idx = p;
        }
    }
    cout << idx << " " << len;
}


signed main(){
    setupIO();
    int Test = 1;
//    cin >> Test;
    for ( int i = 1 ; i <= Test ; i++ ){
        Whisper();
        if (i < Test) cout << '\n';
    }
}

• Subtask 1: 100 / 100