how to find missing number in int array in c#

prabhu p

10y23kVisual Basic .NET

In int array from 0 to 10

{0,1,2,3,4,6,7,8,9} here 5 is missing

6 Replies

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Amit Gupta10y ago
Hey Prabhu
Use below snippet and achieve your solution

var list = new List(new[] { 1, 2, 4, 7, 9 }); var result = Enumerable.Range(0, 10).Except(list);

Do close the thread by accepting the answer if it solves your problem
Tapan Patel10y ago
well here is something interesting. considering that you will have one missing element, you can use little bit of Maths to get the missing number. Just sum them up and take a look at below performance stats.
Pravin More10y ago
Hey Prabhu:)
I f I have understood your requirement correctly then below is perfect clean and simple solution for you.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace CSharpCorner
{
public static class MissingInteger
{
public static void Main(string[] args)
{
var missingNumbers = FindMissingNumber();
Console.WriteLine("Missing numbers in array are:\n");
foreach (var num in missingNumbers)
{
Console.WriteLine(num);
}
Console.ReadLine();
}
private static IEnumerable FindMissingNumber()
{
var list = new List(new[] { 0,1,2,3,4,6,7,8,9 });
var missingNumbers = Enumerable.Range(0, 10).Except(list);
return missingNumbers;
}
}
}
it working as expected.
Please accept answer if it works for you.
Salman Beg10y ago
Hi. Then in that case you can directly check with 5. if(arr[i]==5) Or else write all the code in a function and call it by which number you want to search as a parameter and in that method compare arr[i] with that parameter. Try it once otherwise i will write for you. Thanks.
prabhu p10y ago
thanks for reply
but i need instead fixing ofint chkExist = 5; to dynamic
Salman Beg10y ago
Hi.
static void Main(string[] args)
{
int chkExist = 5;
int cnt = 0;
int[] arr = new int[] { 0, 1, 2, 3, 4, 6, 7, 8, 9 };
for (int i = 0; i < arr.Length; i++)
{
if (arr[i] == chkExist)
{
cnt++;
}
}
if (cnt > 1)
{
Console.WriteLine("Number 5 Exist");
}
else
{
Console.WriteLine("Number 5 not Exist");
}
Console.ReadKey();
}
An array stores a fixed-size sequential collection of elements of the same type. So that's the reason why i run a loop from i=0 to i
Here i checked for particular number but if you have some other requirement then you can change.
Thanks.