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Showing posts with label Programming. Show all posts
Showing posts with label Programming. Show all posts

## Sunday 7 November 2021

### len( ) vs count( ) | Python String

Python String method len( ) is used to get the length of the given string.

name = "Welcome to techies sphere"

print(len(name))

Output: 25

Python String method count( ) is used to get the number of occurrences of a substring in the given string.

string = "Welcome to techies sphere."

subString = "to"

print(string.count(subString))

Output: 1

Syntax of count( ) method:

string.count( subString, start, end )

Parameters:

subString - string whose count is to be found.

start (Optional) - starting index within the string where count starts.

end (Optional) - ending index within the string where count ends.

string = "Welcome to techies sphere, to learn and grow."

subString = "to"

print(string.count(subString, 5, 30))

Output: 1

## Thursday 22 April 2021

### Recursion in C

Recursion is a process in which a function calls itself. In a programming language, if a program allows calling of a function inside the same function, then the function is termed as recursive function and this  process of calling itself is called Recursion.

There are two main requirements for a function to be recursive:

1. Terminating condition -  the function must return when the terminating condition is satisfied.

2. Recursive call - the function must call itself.

Example:-

int fun()

{

...

...

fun();

...

...

}

Here we can see that, the function fun( ) calls itself.

C program:-

C program to calculate the the sum of the ‘nth’ number using recursion.

#include <stdio.h>

int fun(int n)

{

if (n == 0)

return 0;

else

return fun(n - 1) + n;

}

int main()

{

int sum = 0, x;

printf("number");

scanf("%d", &x);

sum = fun(x);

printf("%d\n", sum);

return 0;

}

## Sunday 11 April 2021

### Sum of two number without using '+' operator

Idea 1:-

A half adder has two inputs for the two bits to be added and two outputs one from the ‘sum’ and the other from the ‘carry’ into the higher adder position. A circuit is called a carrying  signal from the addition of the sum of the less significant bits from the X-OR gate the out from AND gate.

Truth table :-

 A B SUM CARRY 0 0 0 0 0 1 1 0 1 0 1 0 1 1 0 1

In the truth table.  you can see I have provided all possible combinations of  A and B. Now if you observe the truth table clearly,  the sum is nothing but A X-or  B. As we know in X-or two different bits give the output  1.

Carry is equal to A and B because we have like 1, 1 input combination the output is equal to one. Therefor

SUM = A  XOR  B

Carry = A  AND  B

C program

#include <stdio.h>

int main()

{

int a, b, sum, carry;

printf("a=");

scanf("%d", &a);

printf("b=");

scanf("%d", &b);

while (b != 0)

{

sum = a ^ b;

carry = (a & b) << 1;

a = sum;

b = carry;

}

printf("sum = %d", sum);

return 0;

}

Explanation of program

Step 1:  Declared two integer type variable a and b. sum and carry taken from to logic gate which is XOR and AND.

Step 2: Give the input in an integer type variable ‘a’ and ‘b’ by scanf() function.

Step 3: Use while loop check b is not equal to zero. the sum is equal to a^b then after carry is equal to a&b <<1 . and stored the value of sum in a. and stored the value of carry in b.

Step 4: Print the sum.

Output:-

Idea 2

Using while loop

C program

#include <stdio.h>

int main()

{

int a, b;

printf("a=");

scanf("%d", &a);

printf("b=");

scanf("%d", &b);

if (b > 0)

{

while (b != 0)

{

a++;

b--;

}

}

else if (b < 0)

{

while (b != 0)

{

a--;

b++;

}

}

printf("sum = %d\n", a);

return 0;

}

Output:-

### While loop in c

A while loop allows a part of the code to be executed multiple times depending upon a given Boolean condition. it called a pre-tested loop. Then the ‘While loop’ is mostly used in the case where the number of repetitions is no known in advance.

Syntax of while loop:-

While(condition)

{

Statement;

Increament/decreasement;

}

Flowchart:-

Example:-

Problem 1

Write a C program to calculate the sum of two numbers without using the plus operator.

Algorithm

Step 1   a++;  b--;

Step 2   Repeat Step 1 until b becomes 0

Program of the above problem

#include <stdio.h>

int main()

{

int a, b;

printf("a=");

scanf("%d", &a);

printf("b=");

scanf("%d", &b);

while (b != 0)

{

a++;

b--;

}

printf("sum = %d\n", a);

return 0;

}

Output:-

Note:  This logic is design for only positive integers.

Problem 2

Write a C program to the counting of the number 1 to 10 using a while loop.

#include<stdio.h>

int main()

{

int i=1;

while(i<=10)

{

printf("%d\n", i);

i++;

}

return 0;

}

Output:-

Problem 3

Write a C program to print the 2s table using a while loop.

#include <stdio.h>

int main()

{

int a, n, i;

printf("number");

scanf("%d", &n);

(i = 1);

while (i<=n)

{

a = 2 * i;

{

printf("%d\n", a);

}

i++;

}

}

Output:-

## Friday 9 April 2021

### Some basic C programs using Conditional Operator

Conditional operator simply returns one value when the condition is true and returns another value if the condition is false. It also knows as a ternary operator.

Syntax of a ternary operator

(condition) ? Expression: Expression;

Example

(a>0)?1:0; evaluates to true so 1.

Now understand the ternary operator with the help of some basic problem.

Problem 1

Write a C program to check the numbers are positive or negative.

#include <stdio.h>

int main()

{

int a, c;

printf("Enter the number ");

scanf("%d", &a);

c = (a>0) ? printf("positive number ") : printf("Negative number ");

// (a > 0) ? printf("positive number") : printf("Negative number");

}

Understanding the above code:

Declared two integer type variables which are a and c.

Input is taken in variable ‘a’ by  ‘scanf( )’ function.

Integer type variable c is used to store the decision based upon the condition by the compiler.

Output

Using this in the above code

(a > 0) ? printf("positive number") : printf("Negative number");

With both the code output is similar.

Problem 2

Write a C program to determine the greatest number between the three numbers.

#include <stdio.h>

int main()

{

int a, b, c, big;

printf("a=");

scanf("%d", &a);

printf("b=");

scanf("%d", &b);

printf("c=");

scanf("%d", &c);

big = a > b ? (a > c ? a : c) : (b > c ? b : c);

printf("Greatest number %d\n", big);

}

Output

## Wednesday 7 April 2021

### Conditional Operator in C

Conditional operator is a Ternary operator available in list of operators in the C language. It requires three operands. Conditional statements are used to make decision based upon condition. Ternary operator requires two special symbols (‘?’ and ‘:’) to express it.

The program execution of conditional operator is just like if-else conditional statement.

Syntax of conditional operator

Expression 1? Expression 2: Expression 3;

Working of Ternary Operator

As in Expression 1? Expression 2:  Expression3. Expression 1 is the Boolean expression. If Expression1 evaluates to 0 which is a Boolean expression then that simply means FALSE and if the Expression1 evaluates to 1 this simply means TRUE therefore Expression3 or Expression2 will get evaluated based on Expression1.

For example

#include<stdio.h>

int main ()

{

int a, c;

printf("Enter the number  ");

scanf("%d", &a);

c = (a>5) ? printf("True") : printf("False");

}

Output:

## Tuesday 30 March 2021

### String Format in Python

Formatting string enables the capability to add dynamic content or string to it in an easy way. It allows to update contents in a string in simpler way.

String Format using format () method

Syntax: template_string.format(positional_args, keyword_args)

The template string contains the replacement fields which can be replaced using the positional_args and keyword_args used in the method. The method returns the formatted string.

In the template string, the replacements fields are enclosed within curly braces “{  }”. Rest of the string content remains unchanged.

Using positional arguments

print('{0} {1} the {2} nicely'.format('This', 'formats', 'string'))

Here,` <template_string>` is `'`{0} {1} the {2} nicely`'`. The replacement fields are `{0}`, `{1}`, and `{2}`` `with zero-based positional arguments 'This', 'formats', 'string'. The replacements fields are replaced with the corresponding positional arguments by the format method.

Using keyword arguments

print('{name} is {age} years old'.format(name='Python', age= 30))

Here, the replacement fields are `{name}`, `{age``}and the corresponding keyword arguments with values. Each fields are replaced with corresponding keyword argument values.`