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Maximum Product of Two Elements in an Array - Easy - LeetCode - MiniTV

Maximum Product of Two Elements in an Array - Easy - LeetCode - मिनी टीवी

Given the array of integers nums, you will choose two different indices i and j of that array. Return the maximum value of (nums[i]-1)*(nums[j]-1).

 

Example 1:

Input: nums = [3,4,5,2]

Output: 12 

Explanation: If you choose the indices i=1 and j=2 (indexed from 0), you will get the maximum value, that is, (nums[1]-1)*(nums[2]-1) = (4-1)*(5-1) = 3*4 = 12. 

 

Example 2:

Input: nums = [1,5,4,5]

Output: 16

Explanation: Choosing the indices i=1 and j=3 (indexed from 0), you will get the maximum value of (5-1)*(5-1) = 16.

 

Example 3:

Input: nums = [3,7]

Output: 12

 

Constraints:

2 <= nums.length <= 500

1 <= nums[i] <= 10^3

 

Solution:

using System;
using System.Collections.Generic;
using System.Text;

namespace LeetCode.AskGif.Easy.Array
{
    public class MaxProductSoln
    {
        public int MaxProduct(int[] nums)
        {
            int val = 0;
            int max = int.MinValue;
            for (int i = 0; i < nums.Length-1; i++)
            {
                for (int j = i+1; j < nums.Length; j++)
                {
                    val = (nums[i] - 1) * (nums[j] - 1);
                    if (val > max)
                    {
                        max = val;                        
                    }
                }
            }

            return max;
        }
    }
}

 

Time Complexity: O(n^2)

Space Complexity: O(1)

 

Unit Tests:

using LeetCode.AskGif.Easy.Array;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using System;
using System.Collections.Generic;
using System.Text;

namespace CodingUnitTest.Easy.Array
{
    [TestClass]
    public class MaxProductSolnTests
    {
        [TestMethod]
        public void MaxProductSoln_First()
        {
            var nums = new int[] { 3, 4, 5, 2 };
            var output = 12;
            var res = new MaxProductSoln().MaxProduct(nums);

            Assert.AreEqual(res, output);
        }

        [TestMethod]
        public void MaxProductSoln_Second()
        {
            var nums = new int[]{1, 5, 4, 5};
            var output = 16;
            var res = new MaxProductSoln().MaxProduct(nums);

            Assert.AreEqual(res, output);
        }

        [TestMethod]
        public void MaxProductSoln_Third()
        {
            var nums = new int[]{3, 7};
            var output = 12;
            var res = new MaxProductSoln().MaxProduct(nums);

            Assert.AreEqual(res, output);
        }
    }
}