How to Work with Boolean Function in C
Anyone Please Tell Me, What Is Wrong in This Code #Include Bool Func(Char *, Int); Void Main() { Char *A="Interview"; If(Func(A,9)) { Printf("True"); } Else {...
Anyone please tell me, what is wrong in this code
#include<stdio.h>
bool func(char *,int);
void main()
{
char *a="Interview";
if(func(a,9))
{
printf("True");
}
else
{
printf("False");
}
}
bool func(char *s, int len)
{
if(len < 2)
return true;
else
return s[0] == s[len-1] && func(&s[1], len-2);
}
I believe this function always returns TRUE. This is an interview question. But, when I try to compile this, it shows 6 errors..
2 Answers
I'm going to guess it doesn't know what bool and true are. bool is not a primitive data type in C you need an extra include:
#include <stdbool.h>
The second part of your question? Does it always return TRUE?
No:
When you come into the function you'll skip the first return because your length is 9. So instead you'll return if true only if:
return s[0] == s[len-1] && func(&s[1], len-2)
Is true. You can skip the recursive logic here because it's not modifying your string, just look at the first part:
s[0] // this has to be 'I'
== // we need so what we compare against has to be 'I' as well
s[len-1] // This will be 'w'
So... that's not going to return true... who cares about ANDing (&&) the recursive part? I suspect the compiler will even optimize that out because everything here is hardcoded.
You just have to include the right header.
#include <stdbool.h>
Or, you can use _Bool type, which don't need any inclusion. bool is just an alias from this type. By the way, don't forget to compile in C99.
Marcus Vance is a cybersecurity auditor and technology writer dedicated to educating the public about online safety, data privacy regulations, enterprise security, and emerging cyber threats.
