# Find out Power without Using POW Function in C

The function pow() is used to calculate the power of a given integer. Now in this article we will going to understand with a help of a program how to calculate the power of a integer without using the function pow() in C.

## Using for loop for Determining the Power of Given Integer

Imagine you need to locate a ^ b. The easiest method is to multiply a by b times using a loop.

• Let a ^ b be the input. The base is a, while the exponent is b.
• Using a loop, execute the following instructions b times
• power = power * a
• The power system has the final solution, a ^ b.

Let's understand the above approach better with an example of a program in C:

Output:

```Enter Base: 5
Enter Power: 3
5 ^ 3 = 125
..........................
Process executed in 3.22 seconds
Press any key to continue.
```

Explanation

The code above has an O (N) time complexity, where N is the exponent. O is the space complexity (1).

### Using While loop:

Output:

```enter the number and its exponential :
5
4
5 ^ 6 = 625
..........................
Process executed in 0.11 seconds
Press any key to continue.
```

Explanation

Long Long Int is twice as large as Long Int. The format specifier for long long int is percent lld.

## Using Recursion to find the Power of Given Integer

Assume that a ^ b is the input. The power of 'a' will increase by one with each recursive call. To obtain a ^ b, we call the recursive function b twice.

• Let Pow ( a, b ) be the recursive function used to calculate a ^ b.
• Simply return 1 if b == 0; else, return Pow (a, b -1) * a.

Let's understand the above approach better with an example of a program in C:

Output:

```Enter Base: 5
Enter Power: 4
5 ^ 4 = 625
..........................
Process executed in 1.22 seconds
Press any key to continue.
```

Explanation:

In the above example of a code in C, time complexity would be exponent N, O(N) & O(N) space complexity, internal stack.