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Find Numbers with Even Number of Digits - Array - Easy - LeetCode - MiniTV

Find Numbers with Even Number of Digits - Array - Easy - LeetCode - मिनी टीवी

Given an array nums of integers, return how many of them contain an even number of digits.

 

Example 1:

Input: nums = [12,345,2,6,7896]

Output: 2

Explanation: 

12 contains 2 digits (even number of digits). 

345 contains 3 digits (odd number of digits). 

2 contains 1 digit (odd number of digits). 

6 contains 1 digit (odd number of digits). 

7896 contains 4 digits (even number of digits). 

Therefore only 12 and 7896 contain an even number of digits.

 

Example 2:

Input: nums = [555,901,482,1771]

Output: 1 

Explanation: 

Only 1771 contains an even number of digits.

 

Constraints:

1 <= nums.length <= 500

1 <= nums[i] <= 10^5

 

Solution:

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

namespace LeetCode.AskGif.Easy.Array
{
    public class FindNumbersSoln
    {
        public int FindNumbers(int[] nums)
        {
            int res = 0;
            for (int i = 0; i < nums.Length; i++)
            {
                if (IsEvenCount(nums[i]))
                {
                    res++;
                }
            }
            return res;
        }

        private bool IsEvenCount(int num)
        {
            int count = 0;
            while(num != 0)
            {
                count++;
                num = num / 10;
            }

            return count % 2 == 0;
        }
    }
}

 

Time Complexity: O(n) Considering the length of the digit is finite.

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 FindNumbersSolnTests
    {
        [TestMethod]
        public void FindNumbersSoln_First()
        {
            var arr = new int[] { 12, 345, 2, 6, 7896 };
            var output = 2;
            var res = new FindNumbersSoln().FindNumbers(arr);

            Assert.AreEqual(res, output);
        }

        [TestMethod]
        public void FindNumbersSoln_Second()
        {
            var arr = new int[] { 555, 901, 482, 1771 };
            var output = 1;
            var res = new FindNumbersSoln().FindNumbers(arr);

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