C Exercises: Calculate the sum of the series 1 +11 + 111 + 1111 + .. n terms
C For Loop: Exercise-26 with Solution
Write a program in C to find the sum of the series 1 +11 + 111 + 1111 + .. n terms.
Pictorial Presentation:

Sample Solution:
C Code:
#include <stdio.h>
void main()
{
int n,i;
long sum=0;
long int t=1;
printf("Input the number of terms : ");
scanf("%d",&n);
for(i=1;i<=n;i++)
{
printf("%ld ",t);
if (i<n)
{
printf("+ ");
}
sum=sum+t;
t=(t*10)+1;
}
printf("\nThe Sum is : %ld\n",sum);
}
Sample Output:
Input the number of terms : 5 1 + 11 + 111 + 1111 + 11111 The Sum is : 12345
Flowchart:

C Programming Code Editor:
Improve this sample solution and post your code through Disqus.
Previous: Write a program in C to display the n terms of square natural number and their sum.
Next: Write a c program to check whether a given number is a perfect number or not.
What is the difficulty level of this exercise?
Test your Programming skills with w3resource's quiz.
C Programming: Tips of the Day
How to initialize array to 0 in C?
Global variables and static variables are automatically initialized to zero. If you have simply-
char ZEROARRAY[1024];
at global scope it will be all zeros at runtime. But actually there is a shorthand syntax if you had a local array. If an array is partially initialized, elements that are not initialized receive the value 0 of the appropriate type. You could write:
char ZEROARRAY[1024] = {0};
The compiler would fill the unwritten entries with zeros. Alternatively you could use memset to initialize the array at program startup:
Ref : https://bit.ly/3cvqplP
- New Content published on w3resource:
- HTML-CSS Practical: Exercises, Practice, Solution
- Java Regular Expression: Exercises, Practice, Solution
- Scala Programming Exercises, Practice, Solution
- Python Itertools exercises
- Python Numpy exercises
- Python GeoPy Package exercises
- Python Pandas exercises
- Python nltk exercises
- Python BeautifulSoup exercises
- Form Template
- Composer - PHP Package Manager
- PHPUnit - PHP Testing
- Laravel - PHP Framework
- Angular - JavaScript Framework
- Vue - JavaScript Framework
- Jest - JavaScript Testing Framework