## 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
• C++
• Java
• Python
• C#
• 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++)
{
}
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++)
{
}

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++)
{
}
}
}

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

n = 5
i = 1
while i <=n :
i = i + 1
```
```//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++)
{
}
}
}
```
```<?php
//PHP Program To Find The Sum Of First N Natural Numbers

\$n = 5;
for (\$i = 1; \$i <= \$n; \$i++)
```
```//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++)
{
}
return 0;
}

```

#### Output

```Sum Of First N Natural Numbers : 15
```

## Recommended Programs

Program for left array rotation
Program to find square root of a number