Cod sursa(job #2888732)

Utilizator Ilie_MityIlie Dumitru Ilie_Mity Data 11 aprilie 2022 19:43:28
Problema Xor Max Scor 90
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 1.49 kb
//Ilie Dmitru
#include<fstream>
#include<cstdio>
typedef long long int ll;
const int NMAX=100005;
const ll MOD=194767;
const int maxBIT=1<<20;

std::ifstream f("xormax.in");
std::ofstream g("xormax.out");

int trie[NMAX*21][2], trieCnt, triePos[NMAX*21];

void push(int x, int pos)
{
    int i, val, index=0;
    for(i=20;i>-1;--i)
    {
        val=(x>>i)&1;
        if(!trie[index][val])
            trie[index][val]=++trieCnt;
        index=trie[index][val];
    }
    triePos[index]=pos;
}

int findMax(int x, int& startPos)
{
    int i, val, res=0, index=0;
    for(i=20;i>-1;--i)
    {
        val=!((x>>i)&1);
        if(trie[index][val])
        {
            res|=1<<i;
            index=trie[index][val];
        }
        else
            index=trie[index][!val];
    }
    startPos=triePos[index];
    return res;
}

char s[NMAX*8];
int v[NMAX];

int main()
{
    int i, N, x=0, r, ans=0, pos, bestStart=-1, bestEnd=-1;
    f>>N;
    f.get();
    f.getline(s, NMAX*8);
    for(i=pos=0;s[i];++i)
    {
        if(s[i]!=' ')
            x=x*10+s[i]-'0';
        else
            v[pos++]=x, x=0;
    }
    v[pos]=x;
    push(0, -1);
    x=0;
    for(i=0;i<N;++i)
    {
        x^=v[i];
        r=findMax(x, pos);
        push(x, i);
        if(r>ans)
        {
            ans=r;
            bestStart=pos;
            bestEnd=i;
        }
    }
    g<<ans<<' '<<bestStart+2<<' '<<bestEnd+1;
    f.close();
    g.close();
    return 0;
}