C Programming: Perfect square

C Programming Mathematics: Exercise-29 with Solution

Write a C programming to get the smallest number of square numbers that add up to an integer n.

In mathematics, a perfect square is a number that can be expressed as either the product of an integer by itself or as the second exponent of an integer..

Sample Data:
14 = 3² + 2² + 1²
Output – 3
15 = 3² + 2² + 1² + 1²
Output - 4
16 = 4²
Output – 1
17 = 4² + 1²
Output – 2

Sample Solution:

C Code:

#include <stdio.h>
#include <stdlib.h>
#include <mem.h>
int test(int n) {
  int * nums = (int * ) malloc((n + 1) * sizeof(int));
  memset(nums, 10000, (n + 1) * sizeof(int));
  nums[0] = 0;
  for (int i = 1; i <= n; i++)
    for (int j = 1; j * j <= i; j++)
      nums[i] = nums[i] < nums[i - j * j] + 1 ? nums[i] : nums[i - j * j] + 1;
  return nums[n];
}

int main(void) {
  int n = 14;
  printf("%d number of square numbers equal to %d", test(n), n);
  n = 15;
  printf("\n%d number of square numbers equal to %d", test(n), n);
  n = 16;
  printf("\n%d number of square numbers equal to %d", test(n), n);
  n = 17;
  printf("\n%d number of square numbers equal to %d", test(n), n);
}

Sample Output:

3 number of square numbers equal to 14
4 number of square numbers equal to 15
1 number of square numbers equal to 16
2 number of square numbers equal to 17

Flowchart:

C Programming Code Editor:

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