CODEWITHSUNDEEP
c#
FFLS
FFLS

Reputation: 574

Removing duplicate lines from a list based on specific columns

I believe that this is similar to this but I was not able to apply the same solution.

I have a list with several columns:

    public struct InfoForGraph
    {
        public float a{ get; set; }
        public double b{ get; set; }
        public double c { get; set; }
        public double d { get; set; }
        public double e { get; set; }
        public double f { get; set; }
        public double g { get; set; }
        public double h { get; set; }
        public double i { get; set; }
        public double j { get; set; }
    }

I would like to remove duplicate lines from this list but only if specific fields match. If I do a distinct with the whole table, these lines will not be erased. Also, I don't care with the repeated lines, I just wanna keep one of them.

Input:

2.67|1.84|420|400|1608039|808|3117|1|2|3|4
2.68|1.84|420|401|1608039|808|3269|1|2|3|4

Output expected:

2.67|1.84|420|400|1608039|808|3117|1|2|3|4

So, if columns 1,2,5,6,8,9,10 have the same value, I should keep only the first return (deleting the 2nd, 3rd, where all these fields match.)

Any ideas?

Upvotes: 2

Views: 103

Answers (1)

Sach
Sach

Reputation: 10393

For simplicity, I narrowed down your condition to say that two objects are equal if InfoForGraph.b and InfoForGraph.c are equal. You get the idea and change your comparer as you like.

public class InfoComparer : IEqualityComparer<InfoForGraph>
{
    public bool Equals(InfoForGraph x, InfoForGraph y)
    {
        if (x.b == y.b && x.c == y.c)
            return true;
        else
            return false;
    }

    public int GetHashCode(InfoForGraph obj)
    {
        unchecked
        {
            int hash = 17;
            hash = hash * 23 + obj.b.GetHashCode();
            hash = hash * 23 + obj.c.GetHashCode();
            return hash;
        }
    }
}

Then call Distinct() on it.

var unique = list.Distinct(new InfoComparer());

Upvotes: 4

Related Questions