Recently I was solving problem Sad Powers. In the editorial of the problem it is mentioned that sqrt() function of c++ has some precision issues. On using the function in my problem on some value gives me wrong answer. After looking others solution I observed that some have used additional checks. e.g. If square root of value x is required then many solutions have checked for both x and (x-1) /(x+1). I could not understand why that additional check is required.
Can anybody please tell why this additional check is required or what are the issues with sqrt() function?