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Java-based LeetCode algorithm problem solutions, regularly updated

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package g0101_0200.s0152_maximum_product_subarray;

// #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Array #Dynamic_Programming
// #Dynamic_Programming_I_Day_6 #Level_2_Day_13_Dynamic_Programming #Udemy_Dynamic_Programming
// #Big_O_Time_O(N)_Space_O(1) #2022_06_25_Time_0_ms_(100.00%)_Space_42.7_MB_(82.46%)

/**
 * 152 - Maximum Product Subarray\.
 *
 * Medium
 *
 * Given an integer array `nums`, find a contiguous non-empty subarray within the array that has the largest product, and return _the product_.
 *
 * It is **guaranteed** that the answer will fit in a **32-bit** integer.
 *
 * A **subarray** is a contiguous subsequence of the array.
 *
 * **Example 1:**
 *
 * **Input:** nums = [2,3,-2,4]
 *
 * **Output:** 6
 *
 * **Explanation:** [2,3] has the largest product 6. 
 *
 * **Example 2:**
 *
 * **Input:** nums = [-2,0,-1]
 *
 * **Output:** 0
 *
 * **Explanation:** The result cannot be 2, because [-2,-1] is not a subarray. 
 *
 * **Constraints:**
 *
 * *   1 <= nums.length <= 2 * 10⁴
 * *   `-10 <= nums[i] <= 10`
 * *   The product of any prefix or suffix of `nums` is **guaranteed** to fit in a **32-bit** integer.
**/
public class Solution {
    public int maxProduct(int[] arr) {
        int ans = Integer.MIN_VALUE;
        int cprod = 1;
        for (int j : arr) {
            cprod = cprod * j;
            ans = Math.max(ans, cprod);
            if (cprod == 0) {
                cprod = 1;
            }
        }
        cprod = 1;
        for (int i = arr.length - 1; i >= 0; i--) {
            cprod = cprod * arr[i];
            ans = Math.max(ans, cprod);
            if (cprod == 0) {
                cprod = 1;
            }
        }
        return ans;
    }
}