Comments by Samriddha Chowdhury (Top 13 by date)

@Richard MacCutchan - thank you very much sir. this exactly solves my problem. Sorry for the initial confusion

what I am trying to do is take an input list from the user and checking if there are any duplicates in it and then print which elements are duplicates.

So basically My List1 is the user input and List2 is the List1.Distinct() (I am trying this by hardcoding just to understand how can I extract the duplicate values)

So basically if my input list is like: {1,2,3,4,2,1,5}
Output I am expecting is {1,2} since 1,2 have duplicate values

Hi now I am trying to apply this logic to the following problem : "Take 2 integer lists from user and check if any duplicates present in them". I have written the below code. When I am comparing the lists with each other then I find and print the duplicates but while checking the list itself I am unable to print the duplicates in the list itself.

static void Main(string[] args)
{

/* Inputting 1st list from user */

int x = Convert.ToInt32(Console.ReadLine());

List<int> list = new List<int>();

for (int i = 0; i < x; i++)
{
list.Add(Convert.ToInt32(Console.ReadLine()));
}

/* Inputting 2nd list from user */

int y = Convert.ToInt32(Console.ReadLine());

List<int> ints = new List<int>();

for (int i = 0; i < y; i++)
{
ints.Add(Convert.ToInt32(Console.ReadLine()));
}

/* Comparing both lists and adding duplicates in 3rd list */

List<int> r = new List<int>();

foreach (int i in list)
{
if (ints.Contains(i))
{
if (!r.Contains(i))
{
r.Add(i);
}
}
}

/* Printing message if/if not duplicates found */

/* Checking for duplicates in 1st List */
if (list.Count() != list.Distinct().Count())
{
Console.Write("Duplicates present in list 1");

List<int> temp = list.Distinct().ToList();
List<int> list2 = new List<int>(list);
foreach (int i in list)
{
list2.Remove(i);
}

//Console.WriteLine("Remove:");
foreach (int item in list2)
{
Console.Write(" "+item);
}

}
Console.WriteLine();

/* Checking for duplicates in 2nd List */
if (ints.Count() != ints.Distinct().Count())
{
Console.Write("Duplicates present in list 2");

List<int> l = (ints.Except(ints.Distinct())).ToList();

foreach (var item in l)
{
Console.Write(" " + item);
}
}
Console.WriteLine();

if (r.Count() == 0)
{
Console.WriteLine("No duplicates in comparing 2 lists");
}
else
{
Console.Write("Duplicates found: ");
foreach (var item in r)
{
Console.Write(" " + item);
}
}
Console.WriteLine();
}

Please ignore my previous comment. Yes only 1 is coming up now. I didn't print the list to look at the items
Many thanks sir :)

no the 1 is not coming up. empty list only

yes that is correct. I have changed my code like this

List<int> list = new List<int>() { 1, 1, 2 };
List<int> list1 = new List<int>() { 1, 2 };
List<int> list2 = new List<int>(list);
foreach (int i in list1)
{
list2.Remove(i);
}


and it is also producing empty list

Could you please make the changes in my code itself?

Thank you sir. Could you please help me to rectify the code so that I can get the desired output?

Hi the list2 is empty and prints nothing. How to achieve the result I want? Mind you that I am very new to programming and dont have much experience