Plus-Minus Split

You are given an array $A$ of length $N$. The array can be modified by performing the following operation on it: - Choose an index $i$ ($1 \le i \le N$). - Then, for each index $j$ ($1 \le j \le N$), - If $j \lt i$, add $A_i$ to $A_j$. - If $j \ge i$, subtract $A_i$ from $A_j$ instead. Note that every element of $A$ *must* be modified - you cannot leave elements unchanged. For example,