Submission #826362

#	Time	Username	Problem	Language	Result	Execution time	Memory
826362		hafo	XOR (IZhO12_xor)	C++14	100 / 100	142 ms	59416 KiB

xor

#include <bits/stdc++.h>
#define ll long long
#define ull unsigned ll
#define pb push_back
#define pa pair<int, int>
#define pall pair<ll, int>
#define fi first
#define se second
#define TASK "test"
#define Size(x) (int) x.size()
#define all(x) x.begin(), x.end()
using namespace std;

template<typename T1, typename T2> bool mini (T1 &a, T2 b) {if(a > b) a = b; else return 0; return 1;}
template<typename T1, typename T2> bool maxi (T1 &a, T2 b) {if(a < b) a = b; else return 0; return 1;}

const int MOD = 1e9 + 7;
const int LOG = 20;
const int maxn = 25e4 + 7;
const ll oo = 1e9 + 69;

int n, k, f[maxn];

struct node {
    node* child[2];
    int pos;

    node () {
        for(int i = 0; i < 2; i++) child[i] = NULL;
        pos = oo; 
    }
};

node* root = new node();

bool getbit(int x, int i) {
    return ((x >> i) & 1);
}

struct trie {
    void add(int x, int pos) {
        node* p = root;
        for(int i = 29; i >= 0; i--) {
            int nxt = getbit(x, i);
            if(p -> child[nxt] == NULL) p -> child[nxt] = new node();
            p = p -> child[nxt];
            if(p -> pos == oo) p -> pos = pos;
        }
    }

    int get(int x) {
        node* p = root;
        int ans = oo;
        for(int i = 29; i >= 0; i--) {
            int nxt = getbit(x, i);
            int cur = getbit(k, i);
            if(cur == 0) {
                if(p -> child[nxt ^ 1] != NULL) mini(ans, p -> child[nxt ^ 1] -> pos);
                if(p -> child[nxt] == NULL) return ans;
                p = p -> child[nxt];
            } else {
                if(p -> child[nxt ^ 1] == NULL) return ans;
                p = p -> child[nxt ^ 1];
            }
        }
        mini(ans, p -> pos);
        return ans;
    }

} trie;

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

    //freopen(TASK".inp", "r", stdin);
    //freopen(TASK".out", "w", stdout);

    cin>>n>>k;
    f[0] = 0;
    trie.add(0, 0);
    int ans = 0, p = 1;
    for(int i = 1; i <= n; i++) {
        int x;
        cin>>x;
        f[i] = f[i - 1] ^ x;
        int j = trie.get(f[i]);
        if(maxi(ans, i - j)) p = j + 1;
        trie.add(f[i], i);
    }

    cout<<p<<" "<<ans;
    return 0;
}

• Subtask 1: 100 / 100