Small rework of optimal vs maxsols

I wanted to make the "optimal" and "maxsolutions" options mutually
exclusive, but in the end I decided there is value in keeping both
(e.g. for specifying a limit to the number of solutions when asking
for "all" optimal").

Now optimal cannot be negative anymore, for the same reason of maxsolutions.

The interface user (shell, UI) will have to take care of handling this
in a way that makes sense for the user. Usually this means setting
the maximum number of solutions to UINT_MAX (or a similar very high
number) when the user wants "all optimal".

1 files changed, 3 insertions, 4 deletions

diff --git a/src/nissy.h b/src/nissy.h
index b13f417..c23f338 100644
--- a/src/nissy.h
+++ b/src/nissy.h
@@ -360,8 +360,7 @@ Parameters:
    minmoves  - The minimum number of moves for a solution.
    maxmoves  - The maximum number of moves for a solution.
    maxsols   - The maximum number of solutions.
-   optimal   - If set to a non-negative value, the maximum number of moves
-               above the optimal solution length.
+   optimal   - The maximum number of moves above the optimal solution length.
    threads   - The number of threads to use. Must be less than or equalt to
                the value of the compile-time constant THREADS. If set to 0,
                the default value THREADS will be used.
@@ -393,8 +392,8 @@ nissy_solve(
         unsigned minmoves,
         unsigned maxmoves,
         unsigned maxsolutions,
-        int optimal,
-        int threads,
+        unsigned optimal,
+        unsigned threads,
         unsigned long long data_size,
         const char data[data_size],
         unsigned sols_size,