Memory C language-commonly used library functions

1. Determine whether it is a square number

#include <stdio.h>
#include <math.h>
int main()
{
  int a;
  scanf("%d",&a);
  if(sqrt(a)==(int)sqrt(a))  //sqrt()平方根函数
    printf("Y");
  else
    printf("N");
  return 0;

}

C language commonly used function library http://c.biancheng.net/c/ref/list_288_2.html