1 ^ 2 ^ 3 ^ 4 ^ A[0] ^ A[1] ^ A[2] ^ A[3]
It might be early in the morning and I am missing something, but it has n-1 as its last index. Any insight is appreciated :)
Edit: There is a missing number in the array, thus its last index is n-2. Thanks for the correction, OP.
Let's say that, without loss of generality:
> 1 ^ 2 ^ 3 ^ 4 ^ A[0]=1 ^ A[1]=2 ^ A[2]=3 ^ A[3]=4
However, A is now missing no value. Contradiction.
∎
1 ^ 2 ^ 3 ^ 4 ^ A[0] ^ A[1] ^ A[2] ^ A[3]
It might be early in the morning and I am missing something, but it has n-1 as its last index. Any insight is appreciated :)
Edit: There is a missing number in the array, thus its last index is n-2. Thanks for the correction, OP.