C Programming Basics Problems for Beginners

1. Generating a series of numbers and calculating their sum in V

Generating like 9 99 999 9999 99999 and there sum

#include <stdio.h>

void main()
{   long int n,i,t=9;
	int sum =0;
	printf("Input the number or terms :");
	scanf("%d",&n);
	for (i=1;i<=n;i++)
	{
	  t=t*10+9;
	  sum =sum+t;
	  printf("%d   ",t);
	}
	printf("\nThe sum of the series = %d \n",sum);
}

output :

2.The Sum of Odd Natural Numbers in C

#include<stdio.h>
void main ()
{
    int i,n,odd=0,sum=0;
    scanf("%d",&n);
    for(i=1;i<=n;i++){
if(i%2!=0){
    printf ("  %d",i);
sum=i+sum;
}

}

    printf("\nThe odd numbers are :%d\n",n/2+1);
    printf("The Sum of odd Natural Number upto 10 terms : %d\n",sum);
}

For example, if the user enters 5, the output could be:

Output:

1 3 5
The odd numbers are: 3
The sum of the first 5 odd natural numbers is 9

3.Prime number Checking in C

#include<stdio.h>
void main ()
{
    int i,n,f=0,count=1;
    printf("Enter a number:");
    scanf("%d",&n);
    for(n=1;i<=100;n++){

    for(i=2;i<n;i++){
        if(n%i==0){
f++;
break;

        }

    }
    }
 if(f==0)
            {printf("prime  number ");}
        else
        { printf("prime not number ");}
}

Input:

Enter a number: 5

Output:

prime not number

4.The Sum of Square Natural Number upto 5 terms in C

#include<stdio.h>
void main ()
{
int i, n,square=1,sum=0;
scanf("%d",&n);
printf("The square natural upto 5 terms are :");
for(i=1;i<=n;i++){
    square=i*i;
    printf("%d ",square);
    sum=square+sum;
}
printf("\nThe Sum of Square Natural Number upto 5 terms:%d",sum);
}

Input: 5

Output:
The square natural upto 5 terms are :1 4 9 16 25
The Sum of Square Natural Number upto 5 terms:55

5.The sum of the digits of the Given Number in C

#include<stdio.h>
void main ()
{
int r,n,sum=0;
printf("Enter any number:");
scanf("%d",&n);
while(n>0){
   r=n%10;
   sum=sum+r;
   n=n/10;

}
printf("Sum of the digits of Given Number = %d",sum);
}

Input: Enter any number:567
Output: Sum of the digits of the Given Number = 18

6. Area of Sphere surface in C

#include<stdio.h>
int main()
{
  double radius,area;
  const double pie =3.1416;
  printf("Enter a radius :");
  scanf("%lf",&radius);
  area =4*3.1416*radius*radius;
  printf("Sphere surface is:%.3lf",area);

return 0;
}

Input: Enter a radius: 8

Output: Sphere surface is:804.250