除自身以外数组的乘积

/*
 * Problem: Given an integer array nums, return an array answer such that answer[i] is equal to the product of all the elements of nums except nums[i].
 * Using Java Streams, we can utilize the map function to generate the product of elements except for the current one.
 */
 
import java.util.Arrays;
 
public class Solution {
    public int[] productExceptSelf(int[] nums) {
        int n = nums.length;
        int[] leftProducts = new int[n];
        int[] rightProducts = new int[n];
        
        leftProducts[0] = 1;
        for (int i = 1; i < n; i++) {
            leftProducts[i] = leftProducts[i - 1] * nums[i - 1];
        }
        
        rightProducts[n - 1] = 1;
        for (int i = n - 2; i >= 0; i--) {
            rightProducts[i] = rightProducts[i + 1] * nums[i + 1];
        }
        
        return Arrays.stream(nums)
                     .map(i -> leftProducts[i] * rightProducts[i])
                     .toArray();
    }
}