1 files changed, 100 insertions, 0 deletions

diff --git a/old/2020-unknown-date/cubeutils.c b/old/2020-unknown-date/cubeutils.c
new file mode 100644
index 0000000..4f0a060
--- /dev/null
+++ b/old/2020-unknown-date/cubeutils.c
@@ -0,0 +1,100 @@
+#include <stdio.h>
+#include "utils.h"
+#include "pieces.h"
+#include "cubeutils.h"
+
+int epe_solved[] = {FR, FL, BL, BR};
+int eps_solved[] = {UL, UR, DL, DR};
+int epm_solved[] = {UF, UB, DF, DB};
+
+void cube_to_ep_array(Cube *cube, int ep[12]) {
+  int epe[4], eps[4], epm[4];
+  index_to_perm(cube->epose % factorial(4), 4, epe);
+  index_to_perm(cube->eposs % factorial(4), 4, eps);
+  index_to_perm(cube->eposm % factorial(4), 4, epm);
+
+  int epose[12], eposs[12], eposm[12];
+  index_to_subset(cube->epose / factorial(4), 12, 4, epose);
+  index_to_subset(cube->eposs / factorial(4), 12, 4, eposs);
+  index_to_subset(cube->eposm / factorial(4), 12, 4, eposm);
+  for (int i = 0; i < 4; i++) {
+    swap(&eposs[eps_solved[i]], &eposs[i+8]);
+    swap(&eposm[epm_solved[i]], &eposm[i+8]);
+  }
+
+  for (int i = 0, ie = 0, is = 0, im = 0; i < 12; i++) {
+    if (epose[i]) ep[i] = epe_solved[epe[ie++]]; 
+    if (eposs[i]) ep[i] = eps_solved[eps[is++]]; 
+    if (eposm[i]) ep[i] = epm_solved[epm[im++]]; 
+  }
+}
+
+void ep_array_to_epos(int ep[12], Cube *cube) {
+  int epe[4], eps[4], epm[4];
+  int epose[12] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
+  int eposs[12] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
+  int eposm[12] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
+  for (int i = 0, ie = 0, is = 0, im = 0; i < 12; i++) {
+    for (int j = 0; j < 4; j++) {
+      if (ep[i] == epe_solved[j]) { epe[ie++] = j; epose[i] = 1; }
+      if (ep[i] == eps_solved[j]) { eps[is++] = j; eposs[i] = 1; }
+      if (ep[i] == epm_solved[j]) { epm[im++] = j; eposm[i] = 1; }
+    }
+  }
+  for (int i = 0; i < 4; i++) {
+    swap(&eposs[eps_solved[i]], &eposs[i+8]);
+    swap(&eposm[epm_solved[i]], &eposm[i+8]);
+  }
+  cube->epose = factorial(4) * subset_to_index(epose, 12, 4)
+                             + perm_to_index(epe, 4);
+  cube->eposs = factorial(4) * subset_to_index(eposs, 12, 4)
+                             + perm_to_index(eps, 4);
+  cube->eposm = factorial(4) * subset_to_index(eposm, 12, 4)
+                             + perm_to_index(epm, 4);
+}
+
+bool solvable(Cube *cube) {
+  /* Since we memorize orientation truncating the last digit, we only need to
+   * check that the permutations have the correct sign. */
+  /* TODO: add check that every integer is in range */
+  int ep[12], cp[12], c[6];
+  cube_to_ep_array(cube, ep);
+  index_to_perm(cube->cp, 8, cp);
+  index_to_perm(cube->centerpos, 6, c);
+  return (perm_sign(ep, 12) ^ perm_sign(c, 6)) == perm_sign(cp, 8);
+}
+
+Cube *solved_cube() {
+  static Cube cube = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
+  return &cube;
+}
+
+bool solved(Cube *cube) {
+  return (cube->eofb == 0 && cube->coud == 0 && cube->cp == 0 &&
+          cube->epose == 0 && cube->eposs == 0 && cube->eposm == 0 &&
+          cube->centerpos == 0);
+}
+
+char *to_string(Cube *cube) {
+  int eo[12], co[8], ep[12], cp[8], cenpos[6];
+  cube_to_eofb_array(cube->eofb, eo);
+  cube_to_coud_array(cube->coud, co);
+  cube_to_ep_array(cube, ep);
+  cube_to_cp_array(cube->cp, cp);
+  cube_to_centerpos_array(cube->centerpos, cenpos);
+
+  char *ret[1000];
+
+  for (int i = 0; i < 12; i++) sprintf(ret, " %s ", edge_string[ep[i]]);
+  sprintf(ret, "\n");
+  for (int i = 0; i < 12; i++) sprintf(ret, "  %d ", eo[i]);
+  sprintf(ret, "\n");
+  for (int i = 0; i < 8; i++) sprintf(ret, "%s ", corner_string[cp[i]]);
+  sprintf(ret, "\n");
+  for (int i = 0; i < 8; i++) sprintf(ret, "  %d ", co[i]);
+  sprintf(ret, "\n");
+  for (int i = 0; i < 6; i++) sprintf(ret, "  %s ", center_string[cenpos[i]]);
+  sprintf(ret, "\n");
+
+  return ret;
+}