program to get Fibonacci series 1,1,2,3,5,8,.... 20th term.

using codeblocks
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//program to get Fibonacci series 1,1,2,3,5,8,.... 20th term.

#include <stdio.h>  //header file
void fibonacci();//function prototype
int main()                 //main function
{
    fibonacci();          // function calling
    return 0;             // returning 0 value
}

void fibonacci()      //function body line/definition
{
    int a=1,b=1,c,i;       // initializing value 1
    printf("%d\n%d\n",a,b);// display of those value
    for(i=1;i<=18;i++)     // running loop for 18 times
    {
        c=a+b;            // finding sum of two numbers
        printf("%d\n",c);//display of that sum
        a=b;             //assigning b to a and c to b.
        b=c;
    }
}


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using turboc++
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//program to get Fibonacci series 1,1,2,3,5,8,.... 20th term.

#include <stdio.h>  //header file
#include<conio.h>//header file
void fibonacci();//function prototype
int main()                 //main function
{
    fibonacci();          // function calling
    getch();             //holds the output
}

void fibonacci()      //function body line/definition
{
    int a=1,b=1,c,i;       // initializing value 1
    printf("%d\n%d\n",a,b);// display of those value
    for(i=1;i<=18;i++)     // running loop for 18 times
    {
        c=a+b;            // finding sum of two numbers
        printf("%d\n",c);//display of that sum
        a=b;             //assigning b to a and c to b.
        b=c;
    }
}

program to get sum of 1,2,3,4,5,.............100 using function

using codeblock
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//program get sum of  1,2,3,4,5,.............100 using function
#include<stdio.h>                      //header file
void sum_series();                          // function prototype/declaration with return type zero.
int main()                              //main function
{
sum_series();                                     // function calling.
return 0;                                       //returns 0 value
}
void sum_series()                              // function body line ; also called function definition
{
int sum=0;           //initialization of sum to zero
 int i;                    // variable declaration 
for(i=1;i<=100;i++)       //loop running from 1 to 100 with increment 1 each time
{
    sum=sum+i;           // summing all the numbers repetitively
}
printf("sum=%d\n",sum);      //output
}


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using turboc++
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//program get sum of  1,2,3,4,5,.............100 using function
#include<stdio.h>                      //header file
#include<conio.h>
void sum_series();                          // function prototype/declaration with return type zero.
void main()                              //main function
{
sum_series();                                     // function calling.
getch();                                       //returns 0 value
}
void sum_series()                              // function body line ; also called function definition
{
int sum=0;           //initialization of sum to zero
 int i;                    // variable declaration 
for(i=1;i<=100;i++)       //loop running from 1 to 100 with increment 1 each time
{
    sum=sum+i;           // summing all the numbers repetitively
}
printf("sum=%d\n",sum);      //output
}

/* here we have used top down approach. i.e calling from top and writing its body line down.
 we can also reverse the process.*/

program to generate series 1,2,3,4,5,.............100 using function

using codeblock
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// to generate 1,2,3,4,5,....100 series using function.
#include<stdio.h>                      //header file
void series();                          // function prototype/declaration with return type zero.
int main()                              //main function
{
series();                                     // function calling.
return 0;                                       //returns 0 value
}
void series()                              // function body line ; also called function definition
{
 int i;                    // variable declaration
for(i=1;i<=100;i++)       //loop running from 1 to 100 with increment 1 each time
{
    printf("%d\n",i);      //output
}
}

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using turboc++
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// to generate 1,2,3,4,5,....100 series using function.
#include<stdio.h>                      //header file
#include<conio.h>
void series();                          // function prototype/declaration with return type zero.
void main()                              //main function
{
series();                                     // function calling.
getch();                                       //holds the output
}
void series()                              // function body line ; also called function definition
{
 int i;                    // variable declaration
for(i=1;i<=100;i++)       //loop running from 1 to 100 with increment 1 each time
{
    printf("%d\n",i);      //output
}
}

/* here we have used top down approach. i.e calling from top and writing its body line down.
 we can also reverse the process.*/

program to get sum of series 1 ,3,5,7,.......nth.

//program  to get sum of series 1 ,3,5,7,.......nth.
#include<stdio.h>
#include<conio.h>
void main()
{
int k,n;
int s=0;printf(enter value of 'n'\n");
scanf("%d",&n);
for(k=1;k<=n;k=k+2)
   {          
       s=s+k;
   }
printf("sum=%d,",s);
getch();
}