Cod sursa(job #3189946)

Utilizator PetraPetra Hedesiu Petra Data 6 ianuarie 2024 18:05:12
Problema Xor Max Scor 10
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 1.45 kb
#include <iostream>
#include <fstream>

#define x first
#define poz second
#define NMAX 100002
#define INF 0x3f3f3f3f
#define TEST(a, b) (((a) & (1 << b)) != 0)

using namespace std;

ifstream fin ("xormax.in");
ofstream fout ("xormax.out");


struct trie {
    int poz;
    trie *bit[2];
    trie() {
        poz = INF;
        bit[0] = bit[1] = NULL;
    }
};

trie *T = new trie;

void add(int val, int pos)
{
    bool bit;
    trie* nd = T;

    for (int i = 25; i >= 0; --i) {
        bit = TEST(val, i);
        if (nd->bit[bit] == 0) {
            nd->bit[bit] = new trie;
        }
        nd = nd->bit[bit];
    }

    nd->poz = pos;
}

int find(int val)
{
    bool bit;
    trie* nd = T;

    for (int i = 25; i >= 0; --i) {
        bit = TEST(val, i);
        if (nd->bit[!bit] == 0) {
            nd = nd->bit[bit];
        } else {
            nd = nd->bit[!bit];
        }
    }

    return nd->poz;
}

int n, v[NMAX];
int main()
{
    fin >> n;
    for (int i = 1; i <= n; i++)
    {
        int x;
        fin >> x;
        v[i] = v[i-1] ^ x;
    }

    add(0, 0);
    int mx = -1, st = 0, dr = 0;

    for (int i = 1; i <= n; i++)
    {
        int aux = find(v[i]);
        if (v[i] ^ v[aux] > mx)
        {
            mx = v[i] ^ v[aux];
            st = aux;
            dr = i;
        }

        add(v[i], i);
    }
    fout << mx << " " << st+1 << " " << dr;
    return 0;
}