Contradictory Polyglots
C and C++ (gcc), 117 107 bytes

-10 bytes thanks to @Steadybox!



#include&lt;stdio.h&gt;
int f(int a,int b){auto c=.5;a-b&amp;&amp;printf("%d %d",c?b&lt;a?b:a:a&gt;b?a:b,c?a-b&gt;0?a-b:b-a:a+b);}


Explanation: In C, auto c=.5 declares an integer variable with the auto storage class (which is the default), which is then initialized to 0, whereas in C++11 it declares a double, which is initialized to 0.5. So the variable's value will be truthy in C++ and falsy in C.

C - max language: Try it online!

C++ - min language: Try it online!