ソースコード

using System;
using System.Collections.Generic;
using System.Linq;

public static class IEnumerableExtensions
{
    public static IEnumerable<TSource> MinElementsBy<TSource, TResult>(
        this IEnumerable<TSource> source,
        Func<TSource, TResult> selector
    )
    {
        var value = source.Min( selector );
        return source.Where( c => selector( c ).Equals( value ) );
    }
}

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