Find the sum of 'n' natural number.( ***lots of things to revise here ***)

 1) 

=> Approach 1

We can ignore the constant time complexity as it does not vary with input.

=> Approach 2 

Order(1) means Order(constant)

*constant means if the input size varies, there is no change in the time complexity.

For each approach there is the best case, average case and worst case.

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