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Input from user to array and Display in Console in C#

I am a Beginner in C# and I was wondering what I got wrong with this code.
I want the user to input the amount of numbers
Then an array with that amount gets created
Then finally I want to display all the numbers in the array.
The Code:
using System;
using System.Threading;
using System.Collections.Generic;
namespace Console_Project_alpha
{
class Program
{
static void Main(string[] args)
{
Console.Write("Enter the amount of numbers: ");
int amount = Convert.ToInt32(Console.ReadLine());
int[] numbers = new int[amount];
string nth = "";
for( int i = 1; i <= amount ; i++)
{
if(i == 1)
{
nth = i + "st";
}
else if( i == 2)
{
nth = i + "nd";
}
else if( i == 3)
{
nth = i + "rd";
}else{
nth = i + "th";
}
Console.Write("\nEnter " + nth + " Number:");
int num = Convert.ToInt32(Console.ReadLine());
for(int j = 0; j <= numbers.Length; j++)
{
numbers[j] = num;
}
}
System.Console.WriteLine(numbers);
}
}
}
Any help is highly appreciated. Thanks in advance

In your code you all time overwriting the same value to all index in
array.
If you want to display values from array in console just iterate after array
Properly worked example based on your code:
class Program
{
static void Main(string[] args)
{
Console.Write("Enter the amount of numbers: ");
int amount = Convert.ToInt32(Console.ReadLine());
int[] numbers = new int[amount];
string nth = "";
int index = 0;
for (int i = 1; i <= amount; i++)
{
if (i == 1)
{
nth = i + "st";
}
else if (i == 2)
{
nth = i + "nd";
}
else if (i == 3)
{
nth = i + "rd";
}
else
{
nth = i + "th";
}
Console.Write("\nEnter " + nth + " Number:");
int num = Convert.ToInt32(Console.ReadLine());
numbers[index] = num;
index++;
}
for (int i = 0; i <= numbers.Length - 1; i++)
{
Console.WriteLine(numbers[i]);
}
Console.ReadLine();
}
}

pyramid pattern in while loop c#

I have to create a program to print pyramid pattern (1 2 33 44 555 666...) and sum the numbers.
Here is my solution:
static void Main(string[] args)
{
int i, j;
i = 1;
int sum = 0;
while (i < 9)
{
for (j = 1; j <= i; j+=2)
{
Console.Write(i);
}
Console.Write("\n");
sum += i;
i++;
}
Console.WriteLine("Summary: " + sum);
Console.ReadLine();
}
And my output:
What am I doing wrong here (wrong summary)?

Here is an optimized and working version of your code:
int sum = 0;
for (int i = 1; i < 9; i++)
{
int current = 0;
for (int j = 1; j <= i; j += 2)
{
Console.Write(i);
current = 10 * current + i;
}
Console.WriteLine();
sum += current;
}
Console.WriteLine("Summary: " + sum);
The main issue is that you were only capturing the value of i (integer being printed) and using that to calculate the summary. As seen here, the current value is captured (for the entire line) within the nested loop and then added to the summary to give you the result you expect.
HTH

Only made small adjustments to your code.
static void Main(string[] args)
{
int i, j;
i = 1;
int sum = 0;
while (i <= 9)
{
for (j = 0; j <= i - 1; j++)
{
Console.Write(i);
sum += i * (int)Math.Pow(10, j);
}
Console.WriteLine();
i++;
}
Console.WriteLine("Sum: " + sum);
Console.ReadLine();
}
If you like to extend your code to let the user pick a number you can do this:
Instead of this line:
while (i <= 9)
You can do this:
Console.WriteLine("Please enter a number between 1 and 9:");
int maxValue = 1;
while (true)
{
if (!int.TryParse(Console.ReadLine(), out maxValue) || maxValue < 1 || maxValue > 9)
{
Console.WriteLine("Wrong input! Try again:");
continue;
}
break;
}
while (i <= maxValue)

Please find not optimized but quick solution
int i, j;
i = 1;
int sum = 0;
while (i < 9)
{
int current = 0;
for (j = 1; j <= i; j += 2)
{
current = 10 * current + i;
Console.Write(i);
}
Console.Write("\n");
sum += current;
i++;
}
Console.WriteLine("Summary: " + sum);
Console.ReadLine();

Giving right answer for N = 2000000 but not passing test cases

Find the sum of all prime numbers not greater than N. For example if user input 5 then prime numbers are 2,3,5 and their sum is 10. It is not passing 4 test cases in which two of them are exceeding the time limit. I have tried several test cases and my code is working fine on them. Here is my code.
public static long sieve_of_eratosthenes(long n)
{
if (n == 1)
{
// If the user input 1.
return (0);
}
else
{
long sum = 0;
bool[] array = new bool[n + 1];
for (long i = 2; i <= n; i++)
{
// Setting all values to true.
array[i] = true;
}
// Eliminating the composite numbers.
for (long j = 2; j < Math.Sqrt(n); j++)
{
if (array[j])
{
long multiple = 1;
for (long k = (j * j); k <= n; k = (j * j) + (j * (multiple++)))
{
array[k] = false;
}
}
}
//Now we have the prime numbers. We just have to add them.
for (int z = 2; z <= n; z++)
{
if (array[z])
{
sum = sum + z;
}
}
return (sum);
}
}
static void Main(string[] args)
{
int noofcases = int.Parse(Console.ReadLine());
for( int i = 0; i < noofcases; i ++)
{
long entry = long.Parse(Console.ReadLine());
Console.WriteLine(sieve_of_eratosthenes(entry));
}
}

check the below code. I wrote simple logic which you can improve
public static class Int32Extension
{
public static bool IsPrime(this int number)
{
if (number <= 1) return false;
if (number == 2) return true;
if (number % 2 == 0) return false;
var boundary = (int)Math.Floor(Math.Sqrt(number));
for (int i = 3; i <= boundary; i += 2)
if (number % i == 0)
return false;
return true;
}
}
then
static void Main(string[] args)
{
int input = 5;
int sum = 0;
for (int i = 0; i < input;)
{
if (!(++i).IsPrime())
continue;
sum += i;
}
Console.WriteLine(sum);
}
Without using Extension Method
public static bool IsPrime(int number)
{
if (number <= 1) return false;
if (number == 2) return true;
if (number % 2 == 0) return false;
var boundary = (int)Math.Floor(Math.Sqrt(number));
for (int i = 3; i <= boundary; i += 2)
if (number % i == 0)
return false;
return true;
}
static void Main(string[] args)
{
int input = 5;
int sum = 0;
for (int i = 0; i < input;)
{
if (!IsPrime(++i))
continue;
sum += i;
}
Console.WriteLine(sum);
}
.Net Fiddle Link : https://dotnetfiddle.net/rEBY9r
Edit : The IsPrime test uses Primality Test With Pseudocode

How to rescue this task?

I wonder how to do or write a code that it will print out no one got 20 points and it has to write a number of line. Everything works except if (is20 == false). How to fix it?
using System;
namespace ConsoleApp1
{
class Program
{
static void Main(string[] args)
{
double[,] points = new double[50, 5];
Random r = new Random();
for (int k = 0; k < 50; k++)
{
for (int j = 0; j < 5; j++)
{
points[k, j] = r.NextDouble() * 5 + 15.5;
if (points[k, j] > 20) points[k, j] = 20;
Console.Write("{0:f1}", points[k, j]);
Console.Write(" ");
}
Console.WriteLine();
}
bestEstimated(points);
Console.ReadLine();
}
public static void bestEstimated(double[,] points)
{
bool is20 = false;
for (int line = 0; line < 50; line++)
{
for (int column = 0; column < 5; column++)
{
if (points[line, column] == 20)
{
Console.WriteLine("20 points got: " + line + " competitor");
is20 = true;
break;
}
}
}
if (is20 == false)
{
Console.WriteLine("No one got 20 points: ");
}
}
}
}

You can set is20=false in inner loop in else part and check it inside outer loop after inner loop.
public static void bestEstimated(double[,] points)
{
bool is20 = false;
for (int line = 0; line < 10; line++)
{
for (int column = 0; column < 5; column++)
{
if (points[line, column] == 20)
{
Console.WriteLine("20 points got: " + line + " competitor");
is20 = true;
break;
}
else
{
is20=false;
}
}
if (!is20)
{
Console.WriteLine("20 points not got: " + line + " competitor");
}
}
if(is20 == false)
{
Console.WriteLine("No one got 20 points: ");
}
}

Just a wild guess from your comments below your question:
public static void bestEstimated(double[,] points)
{
var not20Points = new List<int>();
for (int line = 0; line < 50; line++)
{
bool is20 = false;
for (int column = 0; column < 5; column++)
{
if (points[line, column] == 20)
{
Console.WriteLine("20 points got: " + line + " competitor");
is20 = true;
break;
}
}
if (is20 == false)
{
Console.WriteLine("competitor" + line + " didnt get 20 points"); //also can print it here if ya want...
not20Points.Add(line);
}
}
if (not20Points.Count == 50)
{
Console.WriteLine("No one got 20 points");
}
else
{
Console.WriteLine("Those lines did get 20 points: " + string.Join(",", Enumerable.Range(0, 50).Except(not20Points)));
Console.WriteLine("Those lines didnt get 20 points: " + string.Join(",", not20Points));
}
}
(Updated my version, to only print stuff if atleast one column has 20 points)

Sum of 1000 first primes gives wrong output

i have written a small program to print out the sum of the 1000 first primes, but for some reason i get the wrong result.
namespace ConsoleApplication4
{
class Program
{
static void Main(string[] args)
{
long sum;
sum = 0;
int count;
count = 0;
for (long i = 0; count <= 1000; i++)
{
bool isPrime = true;
for (long j = 2; j < i; j++)
{
if (i != j && i % j == 0)
{
isPrime = false;
break;
}
}
if (isPrime)
{
sum += i;
count++;
}
}
Console.WriteLine(string.Format("{0}",sum));
Console.ReadLine();
}
}
}
result = 3674995 expected = 3682913

The implementation is identifying 1 as a prime, which is not correct; this can be fixed by initializing isPrime as follows.
bool isPrime = i != 1;
This yields the desired result 3682913; however the summand of 0 is also taken into account.

An efficient implementation checks for just prime divisors up to square root of the value; please, notice that all even values are not primes (with only exception - 2):
int count = 1000;
List<long> primes = new List<long>(count) {
2 }; // <- the only even prime
for (long value = 3; primes.Count < count; value += 2) {
long n = (long) (Math.Sqrt(value) + 0.1);
foreach (var divisor in primes)
if (divisor > n) {
primes.Add(value);
break;
}
else if (value % divisor == 0)
break;
}
// 3682913
Console.WriteLine(string.Format("{0}", primes.Sum()));
Console.ReadLine();
Try count = 1000000 and you'll get 7472966967499

long sum;
sum = 0;
int count;
count = 0;
for (long i = 0; count <= 1000; i++)
{
if (i == 1) continue;
bool isPrime = true;
for (long j = 2; j < i; j++)
{
if (i != j && i % j == 0)
{
isPrime = false;
break;
}
}
if (isPrime)
{
sum += i;
count++;
}
}
Console.WriteLine(string.Format("{0}", sum));
Console.ReadLine();