1 files changed, 15 insertions, 0 deletions

diff --git a/src/solvers/coord/eo.h b/src/solvers/coord/eo.h
index b83be01..a0685c4 100644
--- a/src/solvers/coord/eo.h
+++ b/src/solvers/coord/eo.h
@@ -2,6 +2,7 @@ STATIC uint64_t coordinate_eo_coord(cube_t, const void *);
 STATIC cube_t coordinate_eo_cube(uint64_t, const void *);
 STATIC bool coordinate_eo_isnasty(uint64_t, const void *);
 STATIC size_t coordinate_eo_gendata(void *);
+STATIC bool is_eo_even(cube_t);
 
 STATIC coord_t coordinate_eo = {
         .name = "EO",
@@ -18,6 +19,7 @@ STATIC coord_t coordinate_eo = {
                 [AXIS_FB] = TRANS_UFr,
         },
         .is_admissible = &solution_lastqt_cw,
+        .is_solvable = &is_eo_even,
         .sym = {0},
 };
 
@@ -46,3 +48,16 @@ coordinate_eo_gendata(void *data)
 {
         return 0;
 }
+
+STATIC bool
+is_eo_even(cube_t cube)
+{
+        uint8_t c[8], e[12], i, count;
+
+        pieces(&cube, c, e);
+
+        for (i = 0, count = 0; i < 12; i++)
+                count += (e[i] & EOBIT) >> EOSHIFT;
+
+        return count % 2 == 0;
+}