**Perfect Square:**

In mathematics, a

**square number**, sometimes also called a**perfect square**, is an integer that is the square of an integer; in other words, it is the product of some integer with itself. For example, 9 is a square number, since it can be written as 3?×?3. (Text from Wikipedia)
We are going to write a program that checks if the input number is a perfect square or not.

C Program |

**C program to check Perfect Square:**

/** C Program to check Perfect Square **/ #include <stdio.h> int main() { int a, n; printf("Enter a number: "); scanf("%d", &n); for(a = 0; a <= n; a++) { if (n == a * a) { printf("YES"); return 0; } } printf("NO"); return 0; }

**C Program to check Perfect Square using sqrt() function:**

We can perform the same program getting help from sqrt() function. The sqrt() function is bundled with math.h header file. Here is the program:

/* C Program to check Perfect Square using sqrt function */ #include <stdio.h> #include <math.h> int main( { int n, temp; printf("Enter a number: "); scanf("%d",&n); temp = sqrt(n); if(temp*temp == n) printf("YES."); else printf("NO."); return 0; }