C#•2y ago

troubles with list length

class Solution
{
    static void Main(string[] args)
    {
        string line = Console.ReadLine();
        string[] temp = line.Split(' ');
        List<int> nums = new List<int>(temp.Length);
        for (int i = 0; i < temp.Length; i++)
        {
            nums[i] = Convert.ToInt32(temp[i]);
        }
        nums.Sort();
        Console.WriteLine($"Наименьшее значение = {nums[0]}");
        Console.WriteLine($"Наибольшее значение = {nums[nums.Count - 1]}");
    }
}

class Solution
{
    static void Main(string[] args)
    {
        string line = Console.ReadLine();
        string[] temp = line.Split(' ');
        List<int> nums = new List<int>(temp.Length);
        for (int i = 0; i < temp.Length; i++)
        {
            nums[i] = Convert.ToInt32(temp[i]);
        }
        nums.Sort();
        Console.WriteLine($"Наименьшее значение = {nums[0]}");
        Console.WriteLine($"Наибольшее значение = {nums[nums.Count - 1]}");
    }
}

38 Replies

wcasa•2y ago

i wanna get input from user which contains line of numbers, than convert those numbers into list<int>, sort it, so that i could find min and max value what is wrong with this?

Angius•2y ago

You don't need to give the list an initial size And use .Add() to add elements to it

wcasa•2y ago

but why doesnt my method work?

MODiX•2y ago

Retax#0813

REPL Result: Failure

new List<int>(99)[0]

new List<int>(99)[0]

Exception: ArgumentOutOfRangeException

- Index was out of range. Must be non-negative and less than the size of the collection. (Parameter 'index')

- Index was out of range. Must be non-negative and less than the size of the collection. (Parameter 'index')

Compile: 410.056ms | Execution: 23.683ms | React with ❌ to remove this embed.

Angius•2y ago

Because you set the size of the list But it doesn't actually have anything inside So you can't set those things

wcasa•2y ago

wai what

Angius•2y ago

You say "there will be 70 boxes in the truck" But there are no boxes

Anton•2y ago

the constructor sets the capacity, not the count

Angius•2y ago

So you can't put a thing in the 7th box

wcasa•2y ago

that kinda sucks

Angius•2y ago

No, why?

hime•2y ago

The initial capacity you set does not mean there are actually values (like say, 0) in there yet, the internal array is set to that size, but it doesn't let you access it directly unless you actually added it

wcasa•2y ago

i thought c# would fill it with 0s or nulls would be convinient

Angius•2y ago

Makes things easier for you, though. No need for messing with the index and stuff

wcasa•2y ago

i thought it would be slightly slower than assigning with index

Angius•2y ago

Not in any way that would matter

wcasa•2y ago

wait but why would you set size in the first place

hime•2y ago

Sure, if you are adding 1 million items/second it might be 10ms slower

Anton•2y ago

var list = Enumerable.Repeat(default(Type), 99).ToList(); I'd probably use something like this

Angius•2y ago

When the list reaches capacity and you add one more element, the list gets doubled in size That costs some performance

Anton•2y ago

only as an optimization

Angius•2y ago

Telling the list what size to expect causes it to not have to double the capacity It's a minor optimization

wcasa•2y ago

ohhh so, even if i create list of 70 numbers, list.add, than it will add into [0] index, not in [70]th index?

Anton•2y ago

yes

Angius•2y ago

Yeah

wcasa•2y ago

pretty cool than thanks!

Anton•2y ago

and you can't change the count of a list without adding elements until that count reaches the value you need as far as I know

wcasa•2y ago

that makes sense

Angius•2y ago

So you can rewrite

for (int i = 0; i < temp.Length; i++)
{
    nums[i] = Convert.ToInt32(temp[i]);
}

for (int i = 0; i < temp.Length; i++)
{
    nums[i] = Convert.ToInt32(temp[i]);
}

into just

foreach (var t in temp)
{
    nums.Add(int.Parse(t));
}

foreach (var t in temp)
{
    nums.Add(int.Parse(t));
}

Anton•2y ago

this allocates more memory probably but yeah that method is as bad as adding 99 zeros in a loop but there's no other way you can do this with the default list implementation

wcasa•2y ago

btw, is there something better than this?

Angius•2y ago

LINQ

var nums = temp.Select(int.Parse).ToList();

var nums = temp.Select(int.Parse).ToList();

wcasa•2y ago

instead of writing all of this

string line = Console.ReadLine();
        string[] temp = line.Split(' ');
        List<int> nums = new List<int>(temp.Length);
        for (int i = 0; i < temp.Length; i++)
foreach (var t in temp)
{
    nums.Add(int.Parse(t));
}

string line = Console.ReadLine();
        string[] temp = line.Split(' ');
        List<int> nums = new List<int>(temp.Length);
        for (int i = 0; i < temp.Length; i++)
foreach (var t in temp)
{
    nums.Add(int.Parse(t));
}

nah, i mean right from the string to list<int> nums

Angius•2y ago

var nums = Console.ReadLine().Split(' ')
    .Select(int.Parse)
    .ToList();

var nums = Console.ReadLine().Split(' ')
    .Select(int.Parse)
    .ToList();

wcasa•2y ago

without spliting it into array -> converting to list

Angius•2y ago

Ah You can only really take text as input So you will need to split it, and you will need to parse it

wcasa•2y ago

jesus that sucks so badly

Angius•2y ago

Eh, you can always write some simple helper methods

public static class Input
{
    public static bool TryGetInt(out int? number)
    {
        if (int.TryParse(Console.ReadLine(), out var num))
        {
            number = num;
            return true;
        }
        number = null;
        return false;
    }
}

public static class Input
{
    public static bool TryGetInt(out int? number)
    {
        if (int.TryParse(Console.ReadLine(), out var num))
        {
            number = num;
            return true;
        }
        number = null;
        return false;
    }
}

if (Input.TryGetInt(out var num))
{
    Console.WriteLine($"Your number is {num}");
}
else
{
    Console.WriteLine("Not a number");
}

if (Input.TryGetInt(out var num))
{
    Console.WriteLine($"Your number is {num}");
}
else
{
    Console.WriteLine("Not a number");
}

Or some such

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troubles with list length