Product of Array Except Self

two_array.js

/**
 * @param {number[]} nums
 * @return {number[]}
 */
var productExceptSelfTwoArray = function(nums) {
    const prodLeft = [];
    const prodRight = [];
    prodLeft[0] = 1;
    prodRight[nums.length - 1] = 1;
    const ans = [];
    
    for (let i = 1; i < nums.length; i++) {
        const leftIdx = i;
        const rightIdx = nums.length - 1 - i;
        const prevLeft = leftIdx - 1;
        const prevRight = rightIdx + 1;
        
        prodLeft[leftIdx] = nums[prevLeft] * prodLeft[prevLeft];
        prodRight[rightIdx] = nums[prevRight] * prodRight[prevRight];
    }
    
    for (let i = 0; i < nums.length; i++) {
        ans[i] = prodLeft[i] * prodRight[i];
    }
    
    return ans;
};