Submission #938100

#	Time	Username	Problem	Language	Result	Execution time	Memory
938100		tomb	XOR (IZhO12_xor)	C++17	0 / 100	1 ms	344 KiB

xor

#include<bits/stdc++.h>
using namespace std;
#define MAXN 250000
#define ll long long

ll a[MAXN];

int viable(int k, int n, ll x){
    ll val = 0;
    int j = 0;
    for (int i = j; i < k; i++)
        val ^= a[i];
    if (val >= x) return j;
    while (++j + k <= n)
    {
        ll rm = a[j - 1];
        for (int i = 30; i >= 0; i--)
        {
            if (rm & (1 << i) && !(val & (1 << i)))
                val |= (1 << i);
            else if (rm & (1 << i) && val & (1 << i))
                val ^= (1 << i);
        }

        val ^= a[j + k - 1];

        if (val >= x)
            return j;
    }

    return -1;
}


int main(){
    int n; ll x;
    cin >> n >> x;


    for (int i = 0; i < n; i++) cin >> a[i];

    ll lo = 0, hi = n;
    int idx = -1;
    while (lo < hi){
        int mid = (lo + hi + 1) / 2;
        int res = viable(mid, n, x);
        // cout << lo << endl;
        if (res != -1)
            lo = mid, idx = res;
        else 
            hi = mid - 1;
    }

    cout << idx + 1 << " " << lo << endl;
	return 0;

}

• Subtask 1: 0 / 100