C Exercises: Squared sum minus square of 1st 100 numbers

C Programming Challenges: Exercise-22 with Solution

The sum of the squares of the first ten natural numbers is,
1² + 2² + ... + 10² = 385
The square of the sum of the first ten natural numbers is,
(1 + 2 + ... + 10)² = 55² = 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.
Write a C program to find the difference between the sum of the squares of the first one hundred natural numbers and the square of the sum.

C Code:

#include <stdio.h>
int main(void)
{
  unsigned sum1 = 0, sum2 = 0, i;
  for (i = 1; i <= 100; i++) {
    sum1 += i*i;
    sum2 += i;
  }
  printf("%u\n", sum2*sum2 - sum1);
  return 0;
}

Sample Output:

25164150

Flowchart:

C Programming Code Editor:

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