How to input/output & compare "long long" variables in C?

I wrote a program in C. My purpose is testing how "long long" variables work. But the resule comfuse me.

My OS : WinXP

My compiler: TCC (Tiny C Compiler) http://bellard.org/tcc/ version 0.9.25

======== My Source code ========

# include "stdio.h"
# include "math.h"
void main() {
 long long n,i;
 scanf("%lld",&n);
 i=42;
 printf("\nn=%lld",n);
 printf("\ni=%lld",i);
 printf("\ni<=n --> %d",i<=n);
 return;
}

======== The End of Source Code =========

Run the program, I input:

30

Then, the output is:

n=30
i=42
i<=n --> 1

It means " i(42) is smaller than n(30)". Why?

Is there any mistakes when I input a long long variable?

Can you show me the right way?

Thanks 开发者_Python百科for your help!

First, write your main() as

int main(void) { /* ... */ }

Or, as

int main(int argc, char *argv) { /* ... */ }

And then, probably you need a better compiler.

You should call printf("%I64d", var)