res to 0, which will hold the maximum XOR value.res left by 1 to make space for the next bit.
b. Create two maps, pref and pref2, to store the minimum and maximum values with the current prefix.
c. Iterate over the array and update pref and pref2 with the current elements.
d. For each prefix x in pref, calculate the greedy guess y as res ^ 1 ^ x.
e. If x >= y and y is in pref and pref[x] <= pref2[y] * 2, set the last bit of res to 1.res as the maximum XOR value.