ELEPHANT's blog

To xor or not to xor
By ELEPHANT, 11 years ago, In English

Hi

Any ideas how to solve this problem?

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11 years ago, # |
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I think you can do such thing:

  1. Compose answer by getting maximum possible prefix of some size and appending 1 or 0 to it

  2. All that you need then is to be able to check whether some prefix can be obtained or not. To do that you can use linear equations modulo 2

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11 years ago, # |
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After you break that one, you can try this one XMAX

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11 years ago, # |
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//v is input array
long long ans = 0;
while (1)
{
    long long t = *max_element(all(v));
    if (t == 0) break;
    fori(sz(v))
        v[i] = min(v[i], v[i] ^ t);
    ans = max(ans, ans ^ t);
}
write ans;
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