LeetCode 238 Product of Array Except Self - Walkthrough

Compute product of all elements except self for $arr = [1, 2, 3, 4]$ without division. Prefix products: $[1, 1, 2, 6]$ (product of elements before $i$). Suffix products: $[24, 12, 4, 1]$ (product of elements after $i$).

Answer: $prefix[i] \times suffix[i]$. For index $0$: $1 \times 24 = 24$. For index $1$: $1 \times 12 = 12$. For index $2$: $2 \times 4 = 8$. For index $3$: $6 \times 1 = 6$. Result: $[24, 12, 8, 6]$. This handles zeros correctly: if one zero exists, only its position has nonzero result.