Problem 6

Statement
The sum of the squares of the first ten natural numbers is,

1^(2) + 2^(2) + … + 10^(2) = 385

The square of the sum of the first ten natural numbers is,

(1 + 2 + … + 10)^(2) = 55^(2) = 3025

Hence the difference between the sum of the squares of the first ten natural numbers and the square of the sum is 3025 – 385 = 2640.

Find the difference between the sum of the squares of the first one hundred natural numbers and the square of the sum.

Solution
The code, in C.

#include <stdio.h>

int diff(int n)
{
  unsigned long int a=0;
  unsigned long int b=0;
  int i;

  for(i=1;i<=n;i++){
    a+=i*i;
    b+=i;
  }
  b*=b;
  return b-a;
}

int main(void)
{
  printf("%d\n",diff(100));
  return 0;
}

Answer
25164150

No tags for this post.

SPEAK / ADD YOUR COMMENT
Comments are moderated.

XHTML: You can use these tags: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>