Minimum and maximum P98458

Write a procedure

    void min_max(int a, int b, int& mn, int& mx);

to store in @mn@ the minimum of @a@ and @b@, and store in @mx@ the maximum of @a@ and @b@. For instance, if called with @a@ $=7$ and @b@ $= -3$, the values after the call must be @mn@ $=-3$ and @mx@ $= 7$.

Observation

You only need to submit the required procedure; your main program will be ignored.