# Assignment Solution of Loops

## Assignment Solution of Loops in C++

In this article, I am going to give you the solutions that we give you as an assignment in our Loops in C++ article. So, please read our Loops in C++ article, if you have not read it yet. First, try to solve the problem by yourself and then only look at the below solutions.

##### Program to find the sum of first N natural numbers.

Testcase1: input: N=20
Expected output=210
Note: Also select which loop is better to find the first N natural numbers.
Solution: To make a choice of which loop? Letâ€™s understand the question. Here we need to find the sum of N natural numbers.

Letâ€™s say we want to find some of the first 5 numbers. 1,2,3,4,5 sum of these numbers is 1+2+3+4+5. Here I know how many times I need to run the loops. Yes. You guessed it right 5 times as we have 5 numbers. As discussed in our previous article, if we know how many times to execute then the best choice is counter loops (for-loop). However; you can implement it using other loops as well.

```#include <iostream>
using namespace std;
int main ()
{
int sum = 0;
int number;
cout << "Enter the number till you want to find the sum" << endl;
cin >> number;
for (int i = 1; i <= number; ++i)
{
sum += i;
}
cout << sum;
return 0;
}
```

Output:

##### Program to find factorial of a number.

Testcase1: input N=5;
Output=120;

Solution:
Algorithm for finding factorial of a number in C++
1. Declare variables i (for loop) and fact (for storing final answer).
2. Initialize fact with value 1
3. Take input from the user whose factorial u want to find (suppose n here)
4. Run a loop from i=n to i>0
Â  Â  Â  for(i=n;i>0;i – -)
Â  Â  Â  Â  Â fact=fact*i;
5. Print fact on the console window

```#include <iostream>
using namespace std;
int main ()
{
int fact = 1;
int number;
cout << "Enter the number for which you want to find the factorial" << endl;
cin >> number;
for (int i = number; i > 0; --i)
{
fact *= i;
}
cout << fact;
return 0;
}
```

Output:

##### Program to find a palindrome or not.

Testcase1: input:1212121
Output: palindrome
Solution:

```#include <iostream>
using namespace std;
int main ()
{
int number, res = 0, digit = 0;
cout << "enter the number for which you want to chech palindrom or not" << endl;
cin >> number;
int temp = number;
while (number > 0)
{
digit = number % 10;
res = res * 10 + digit;
number /= 10;
}

if (temp == res)
{
cout << "palindrome";
}
else
{
cout << "not palindrome";
}
return 0;
}
```

Output:

##### Program to find GCD between two numbers

Testcase1: input: 81 153
Output: 9
Solution:

```#include<iostream>
using namespace std;
int main ()
{
int num1, num2;
cout << "Enter two numbers for which you want to find GCD " << endl;
cin >> num1 >> num2;

while (num1 != num2)
{
if (num1 > num2)
num1 -= num2;
else
num2 -= num1;
}
cout << num1 << endl;
return 0;
}
```

Output:

Program to Perform banking operation.

Solution: Donâ€™t try this exercise, for now, it is good if we try after discussing class, object, and methods.

Thatâ€™s it for today. We have given the solutions that we give you as an assignment in our Loops in C++ article. If you have a better solution, then please post your solution in the comment box so that other guys will get benefits.Â