Submission #1276573

#	Time	Username	Problem	Language	Result	Execution time	Memory
1276573		MinhKien	XOR (IZhO12_xor)	C++20	100 / 100	1375 ms	60124 KiB

xor

#include <iostream>

using namespace std;

const int N = 2.5e5 + 10;
const int LG = 29;

int n, x, a[N];

struct Trie {
    struct node {
        int child[2];

        node () {
            child[0] = child[1] = -1;
        }
    };

    node nd[N * (LG + 1)];
    int cnt;

    void reset() {
        cnt = 0;
        nd[0] = node();
    }

    void add(int u) {
        int cur = 0;
        for (int i = LG; i >= 0; --i) {
            int c = u >> i & 1;
            if (nd[cur].child[c] == -1) {
                nd[cur].child[c] = ++cnt;
                nd[cnt] = node();
            }
            cur = nd[cur].child[c];
        }
    }

    int Max(int u) {
        int res = 0, cur = 0;
        
        for (int i = LG; i >= 0; --i) {
            int c = u >> i & 1;

            if (nd[cur].child[c ^ 1] != -1) {
                res |= (1 << i);
                cur = nd[cur].child[c ^ 1];
            } else {
                cur = nd[cur].child[c];
            }
        }

        return res;
    }
} T;

int check(int val) {
    int mx = 0, I = 0;
    T.reset();
    for (int i = n - val + 1; i >= 1; --i) {
        T.add(a[i + val]);
        int cur = T.Max(a[i]);
        if (cur >= x) I = i;
    }
    return I;
}

int main() {
    cin.tie(0); cout.tie(0);
    ios_base::sync_with_stdio(false);

    cin >> n >> x;
    for (int i = 1; i <= n; ++i) cin >> a[i];
    for (int i = n; i >= 1; --i) a[i] ^= a[i + 1];

    int l = 1, r = n, ans = -1;
    int I = 0;
    while (l <= r) {
        int mid = (l + r) >> 1;

        int cur = check(mid);
        if (cur > 0) {
            ans = mid;
            I = cur;
            l = mid + 1;
        } else {
            r = mid - 1;
        }
    }

    cout << I << " " << ans << "\n";

    return 0;
}

• Subtask 1: 100 / 100