package Leetcode.Array;

import java.util.Arrays;

/**
 * @author zhengstars
 * @date 2024/03/02
 */
public class ProductOfArrayExceptSelf {
    public static int[] productExceptSelf(int[] nums) {

        // Create a new result array with the same length as the input array
        int[] result = new int[nums.length];

        // Initialize all values in the result array to 1
        Arrays.fill(result,1);

        // Iterate over the nums array starting from the second value
        // Multiply the current result value by the previous nums value
        for(int i = 1; i < nums.length; i++){
            result[i] = result[i - 1] * nums[i - 1];
        }

        // Initialize a variable, right, to keep track of the product of values to the right of the current index
        int right = 1;

        // Iterate over the nums array in reverse order
        // Multiply the current result value by the current right value
        // Update right to be the product of its current value and the current nums value
        for(int j = nums.length - 1; j >=0 ; j--){
            result[j] = result[j] * right;
            right *= nums[j];
        }

        // Return the result array
        return result;
    }

    public static void main(String[] args) {
        // Test Case 1
        int[] nums1 = {1,2,3,4};
        // Print the result of the productExceptSelf method on nums1
        System.out.println(Arrays.toString(productExceptSelf(nums1)));  // Expected output: [24,12,8,6]

        // Test Case 2
        int[] nums2 = {-1,1,0,-3,3};
        // Print the result of the productExceptSelf method on nums2
        System.out.println(Arrays.toString(productExceptSelf(nums2)));  // Expected output: [0,0,9,0,0]
    }
}