Q. Write an algorithm and program to find sum of first n natural numbers?

Sum Of First N Natural Numbers : This section focuses on sum of first n natural numbers algorithm and program. This program should be practiced to improve the coding skills required for various interviews (campus interviews, walk-in interviews), coding rounds etc.

Natural Numbers : Natural numbers include all whole numbers excluding 0.
Given a number n and our task to print the sum of first n natural numbers.

For Example :-

Input : n = 3
Output : 6
Explanation : As we can see that input number is 3. Now, we need to add the natural number till 3 : 1 + 2 + 3 . So, output for the following code is sum of 1 + 2 + 3 = 6. Now let us understand what logic we need to use in this -
1. Firstly, we need to Initialize an integer sum = 0.
2. Loop will run throughout the program.The loop will start from i = 1 to n.
3. Add sum = sum + x.

Algorithm To Find The Sum Of First N Natural Numbers

\\Algorithm To Find The Sum Of First N Natural Numbers
START
Step 1 : Initialize : sum = 0
Step 2 : Loop Starts from x = 1 to n :
            sum = sum + x 
Step 3 : Print sum
Stop

Program To Find The Sum Of First N Natural Numbers

C++

Java

Python

PHP

//C Program To Find The Sum Of First N Natural Numbers
#include <stdio.h> 
  
int main()
{
    int n = 5, add = 0; 
    for (int i=1; i<=n; i++) 
    {
     add = add + i;
    }
    printf("%d",add);
    return 0;
}

//C++ Program To Find The Sum Of First N Natural Numbers
#include <iostream>
using namespace std;

int main()
{
    int n = 5, add = 0; 
    for (int i=1; i<=n; i++) 
    {
     add = add + i;
    }
    cout<<add;
    
    return 0;
}

//Java Program To Find The Sum Of First N Natural Numbers

public class LFC
{
    public static void main(String[] args) {
        
        int n = 5, add = 0; 
        for (int i=1; i<=n; i++) 
        {
         add = add + i;
        }
        System.out.println(add);
    }
}

#Python Program To Find The Sum Of First N Natural Numbers

add = 0
n = 5
i = 1
while i <=n : 
    add = add + i
    i = i + 1
print(add)

//C# Program To Find The Sum Of First N Natural Numbers

using System;
class LFC {
  static void Main() {
      int n = 5, add = 0; 
        for (int i=1; i<=n; i++) 
        {
         add = add + i;
        }
      Console.WriteLine(add);
  }
}

<?php
//PHP Program To Find The Sum Of First N Natural Numbers

$n = 5;
$add = 0; 
for ($i = 1; $i <= $n; $i++)  
    $add = $add + $i;
echo $add;

//C Program To Find The Sum Of First N Natural Numbers
#include <stdio.h> 
  
int main()
{
    int n = 5, add = 0; 
    for (int i=1; i<=n; i++) 
    {
     add = add + i;
    }
    printf("%d",add);
    return 0;
}

Output

Sum Of First N Natural Numbers : 15

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