Rewritten from scratch. Welocme nissy 2.0!

1 files changed, 59 insertions, 0 deletions

diff --git a/old/utils.h b/old/utils.h
new file mode 100644
index 0000000..ee8ac6e
--- /dev/null
+++ b/old/utils.h
@@ -0,0 +1,59 @@
+#ifndef UTILS_H
+#define UTILS_H
+
+#include <stdbool.h>
+#include <stdlib.h>
+
+/* Constants and macros *****************************************************/
+
+#define pow2to11    2048
+#define pow2to12    4096
+#define pow3to7     2187
+#define pow3to8     6561
+#define pow12to4    20736
+#define factorial4  24
+#define factorial6  720
+#define factorial8  40320
+#define factorial12 479001600
+#define binom12on4  495
+#define binom8on4   70
+
+#define min(a,b) (((a) < (b)) ? (a) : (b))
+#define max(a,b) (((a) > (b)) ? (a) : (b))
+
+/* Generic utility functions *************************************************/
+
+void apply_permutation(int *perm, int *set, int n);
+void intarrcopy(int *src, int *dst, int n);
+bool is_perm(int *a, int n);
+bool is_subset(int *a, int n, int k);
+int  sum(int *a, int n);
+void sum_arrays_mod(int *src, int *dst, int n, int m);
+void swap(int *a, int *b);
+
+/* Standard mathematical functions *******************************************/
+
+int binomial(int n, int k);
+int factorial(int n);
+int perm_sign(int a[], int n);
+int powint(int a, int b);
+
+/* Conversions to and from int (base b digits, permutations...) **************/
+
+int  digit_array_to_int(int *a, int n, int b);
+void int_to_digit_array(int a, int b, int n, int *r);
+void int_to_sum_zero_array(int x, int b, int n, int *a);
+int  invert_digits(int a, int b, int n);
+
+void index_to_perm(int p, int n, int *r);
+int  perm_to_index(int *a, int n);
+
+void index_to_subset(int s, int n, int k, int *r);
+int  subset_to_index(int *a, int n, int k);
+
+/* Am I not using these two?
+void index_to_ordered_subset(int s, int n, int k, int *r);
+int  ordered_subset_to_index(int *a, int n, int k);
+*/
+
+#endif