FUNCTIONS
=========

PYTHON
	FUNCTIONAL APPROACH ==> C
	SCRIPTING ==> PERL
	MODULAR APPROACH ==> MODULA3

calculator
	arithmetic
	===========
	trigonometric
	=============
	log
	====
	integration etc.
	===========

function can be a block of code which can be represented with some name and we can use this to perform the specific task.
==> the function cannot execute by itself.
by invoking/calling the function it can perform the task.
Advantages:
	1) solving the complex or larger programs easily.
	2) debugging the application is easy.

How to define the function?
===========================
keyword: def
Syntax:
	def functions-name(parameters/arguments):
		block of statements

How we can call the function?
=============================
Syntax:
	function-name(values for parameters)

Types of Functions
==================
1) Functions without parameters and no return type
===================================================
Syntax:
	def function-name():
		function body

# WRITING A FUNCTION WITHOUT PARAMETERS AND NO RETURN TYPE

# function definition
def findSmall():        # function header
    # function body
    a = int(input("Enter a value:"))
    b = int(input("Enter a value:"))
    c = int(input("Enter a value:"))
    d = int(input("Enter a value:"))

    if a < b and a < c and a < d:
        print("The Smaller value is = ",a)
    elif b < c and b < d:
        print("The Smaller value is = ",b)
    elif c < d:
        print("The Smaller value is = ",c)
    else:
        print("The Smaller value is = ",d)

# function call
findSmall()

2) Functions without Parameters and return type
==============================================
Syntax:
	def function-name():
		function-body
		return value

# WRITING A FUNCTION WITHOUT PARAMETERS AND RETURN TYPE
from importlib.resources import read_binary


def decToBin():
    number = int(input("Enter a decimal:")) # 97

    n = number
    binary = ""

    while n != 0:
        rem = str(n % 2)     # 1 0
        binary = rem + binary   # "1100001"
        n //= 2
    return binary


# result = decToBin()
# print(result)

print(decToBin())

==============================================

# WRITING A FUNCTION WITHOUT PARAMETERS AND RETURN TYPE
from importlib.resources import read_binary


def decToBin():
    number = int(input("Enter a decimal:")) # 97

    n = number
    binary = 0
    power = 1

    while n != 0:
        rem = n % 2     # 1 0
        binary = binary + rem * power   # "1100001"
        power *= 10
        n //= 2
    return binary


# result = decToBin()
# print(result)

print(decToBin())

3) Functions with parameters and no return type
===============================================
Syntax:
	def function-name(parameter-names with comma separation):
		function body

# WRITING A FUNCTION WITH PARAMETERS AND NO RETURN TYPE

def triangleArea(s1,s2,s3):
    s = (s1 + s2 + s3)/2
    area = (s*(s-s1)*(s-s2)*(s-s3)) ** 0.5

    print("The Area of the Triangle is = ",area)

# triangleArea(9,7,5)
# s1 = 10
# s2 = 8
# s3 = 7
#
# triangleArea(s1,s2,s3)

a = 9
b = 7
c = 8

triangleArea(c,a,b)

4) Functions with parameters and return type
============================================
Syntax:
	def function-name(parameters with comma separation):
		function body
		return

# WRITING A FUNCTION WITH PARAMETERS AND RETURN TYPE

def typeTriangle(a,b,c):
    if a == b and a == c and b == c:
        return "It is an Equilateral Triangle."
    elif a == b or a == c or b == c:
        return "It is an Isosceles Triangle."
    elif (a * a + b * b) == c * c or (b * b + c * c) == a * a or (a * a + c * c) == b*b:
        return "It is a Right Angled Triangle."
    else:
        return "It is a scalene Triangle."

# print(typeTriangle(10,10,10))
# a = 9
# b = 7
# c = 9
# print(typeTriangle(a,b,c))
# p = 5
# q = 4
# r = 3
# print(typeTriangle(p,q,r))
print(typeTriangle(10,11,9))