Changeset ded085 in git

Timestamp:

Dec 11, 2009, 4:40:02 PM (13 years ago)

Author:

Frank Seelisch <seelisch@…>

Branches:

(u'spielwiese', '0d6b7fcd9813a1ca1ed4220cfa2b104b97a0a003')

Children:

867e1a39616ddc1692d837af059565a1320e8cc7

Parents:

b54a393fcb8e823c662951c5a6219096fb8a6800

Message:

in ring.cc: completed rChar for Z/n, Z/p^m, and Z/2^m
in ideals.*: made insertion into ideals return TRUE/FALSE instead of void

git-svn-id: file:///usr/local/Singular/svn/trunk@12382 2c84dea3-7e68-4137-9b89-c4e89433aadc

Location:

kernel

Files:

• ideals.cc (modified) (3 diffs)
• ideals.h (modified) (1 diff)
• ring.cc (modified) (1 diff)

kernel/ideals.cc

@@ -541 +541 @@
 
 /*2
-* concat h1 and h2
-*/
-void idInsertPoly (ideal h1,poly h2)
-{
-  if (h2==NULL) return;
+* insert h2 into h1 (if h2 is not the zero polynomial)
+* return TRUE iff h2 was indeed inserted
+*/
+BOOLEAN idInsertPoly (ideal h1, poly h2)
+{
+  if (h2==NULL) return FALSE;
   int j = IDELEMS(h1)-1;
   while ((j >= 0) && (h1->m[j] == NULL)) j--;
@@ -555 +556 @@
   }
   h1->m[j]=h2;
-}
-
-/*2
-* concat h1 and h2 (if h2 is neither zero nor a generator of h1)
-*/
-void idInsertPolyNoDuplicates (ideal h1,poly h2)
+  return TRUE;
+}
+
+/*2
+* insert h2 into h1 (if h2 is neither the zero polynomial
+* nor a generator in h1)
+* return TRUE iff h2 was indeed inserted
+*/
+BOOLEAN idInsertPolyNoDuplicates (ideal h1, poly h2)
 {
   bool h2FoundInH1 = false;
@@ -569 +573 @@
     i++;
   }
-  if (!h2FoundInH1) idInsertPoly(h1, h2);
+  if (!h2FoundInH1) return idInsertPoly(h1, h2);
+  else return FALSE;
 }
 

kernel/ideals.h

@@ -54 +54 @@
 ideal idAdd (ideal h1,ideal h2);
   /* h1 + h2 */
-void idInsertPoly (ideal h1,poly h2);
+BOOLEAN idInsertPoly (ideal h1,poly h2);
   /* h1 + h2 */
-void idInsertPolyNoDuplicates (ideal h1,poly h2);
+BOOLEAN idInsertPolyNoDuplicates (ideal h1,poly h2);
   /* h1 + h2 */
 ideal idMult (ideal h1,ideal h2);

kernel/ring.cc

@@ -766 +766 @@
 }
 
+int binaryPower (const int a, const int b)
+{
+  /* computes a^b according to the binary representation of b,
+     i.e., a^7 = a^4 * a^2 * a^1. This saves some multiplications. */
+  int result = 1;
+  int factor = a;
+  int bb = b;
+  while (bb != 0)
+  {
+    if (bb % 2 != 0) result = result * factor;
+    bb = bb / 2;
+    factor = factor * factor;
+  }
+  return result;
+}
+
 int rChar(ring r)
 {
+  if (rField_is_Ring_2toM(r))
+    return binaryPower(2, (int)(unsigned long)r->ringflagb);
+  if (rField_is_Ring_ModN(r))
+    return (int)mpz_get_ui(r->ringflaga);
+  if (rField_is_Ring_PtoM(r))
+    return binaryPower((int)mpz_get_ui(r->ringflaga),
+                       (int)(unsigned long)r->ringflagb);
   if (rField_is_numeric(r))
     return 0;