Factorial of given number using recursive function.

Recursive Function

The function which calls itself is called recursive function.

Factorial of given number using recursive function.

#include <stdio.h> int factorial(int); int  main() {    int number;       printf("Enter your number:");    scanf("%d", &number);       printf("Factorial of %d is %d\n", number, factorial(number));    return 0; } int factorial(int i) {    if(i<=1) {       return 1;    }    return (i*factorial(i-1)); }

Output of the program

Enter your number:5

Factorial of 5 is 120

Use of built-in C string library function.

// Use of built-in C string library function. #include<stdio.h> int main() {      int len;      char str1[10], str2[10];           puts("Enter String 1:");      gets(str1);           puts("Enter String 2:");      gets(str2);           //Function to find length of given string 1.      len = strlen(str1);      printf("\nLength of String 1 is %d.\n", len);           //Function to compare two strings      if(strcmp(str1,str2)==0)            printf("\nString 1 and String 2 are same.\n");      else            printf("\nString 1 and String 2 are not same.\n");                 //Function to copy string 1 into string 2      strcpy(str2,str1); //this will copy str1 into str2      printf("\nString 2 after execution of strcpy = %s", str2);           return 0; }

Output of the program:

/*Output

Enter String 1:

abc

Enter String 2:

xyz

Length of String 1 is 3.

String 1 and String 2 are not same.

String 2 after execution of strcpy = abc

*/

Square of given number using function with an argument and a return value.

/* C program to find square of given number using function. Use of function with an argument and a return value. */ #include<stdio.h> int square(int); // function prototype declaration. void main() {      int number, answer;           printf("Enter your number:");      scanf("%d", &number);           answer = square(number);  //Call function.           printf("Square of %d is %d.", number, answer); } int square(int n) {      //function logic is written here..      return(n*n); //This will return answer to main function. }

Output of the Program:

Enter your number:5

Square of 5 is 25. 

C program to print Standing Triangle pattern.

C program to print standing triangle pattern. For n = 3, generate pattern as shown below: * * * * * * * * * #include<stdio.h> int main() {      int i, j, N=5;      for(i=0; i<N; i++)        {            for(j=0; j<=i; j++)                 printf("* ");            printf("\n");             }      for(i=0; i<N; i++)        {            for(j=N-1; j>i; j--)                 printf("* ");            printf("\n");             }      return 0; }

Output of the Program:

*

* *

* * *

* *

*

Algorithm to print Fibonacci series up to given number N.

About Fibonacci series 

Each new number in a series is addition of its previous two numbers.

Example of Fibonacci series(for N = 8)

0, 1, 1, 2, 3, 5, 8, 13

Algorithm to print Fibonacci series up to given number N.

Step 1: Start

Step 2: Declare variables N, N1, N2, N3, i.

Step 3: Read value of N from user.

Step 4: if N < 2, display message “Enter number > 2” and go to step 9.

Step 5: Initialize variables N1 = 0, N2 = 1, i = 0

Step 6: Display N1, N2  

Step 7: Compute N3 = N1 + N2

Step 8: Repeat following statements until i <  N - 2

Display N3

N1 = N2

N2 = N3  

N3 = N1 + N2

i  = i + 1

Step 9: Stop

>>> Learn how to convert this algorithm in to C program here.

* * * * *

Algorithm to find factorial of a given number.

Factorial of number n is defined as follow:

      n! = 1 * 2 * 3 * 4 * ....* n

Algorithm to find factorial of a given number N:

Step 1: Start

Step 2: Declare variables: N, fact,  i.

Step 3: Initialize variables

           fact = 1

           i = 1

Step 4: Read value of N from user.

Step 5: Repeat following steps until i = N

           fact =  fact * i

           i = i + 1

Step 6: Print fact variable.

Step 7: Stop

>>> Program to convert this algorithm in to a C program.

Use of pointer to access the Array elements.

Use of pointer to access the Array elements. #include <stdio.h> int main () {        int marks[] = {60, 70, 80, 90, 100};        int i, *p1;        /* let us use pointer to refer array elements */        p1 = marks;        for ( i = 0; i < 5; i++)        {               printf("Value stored at marks[%d] = %d\n", i, *p1 );               p1++;        }        return 0; }

Output of the Program:

Value stored at marks[0] = 60

Value stored at marks[1] = 70

Value stored at marks[2] = 80

Value stored at marks[3] = 90

Value stored at marks[4] = 100