misc integer factorial stuff

crowlogic · Jan 28, 2024 · 24456ef · 24456ef
1 parent b1e2b99
commit 24456ef
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diff --git a/native/Functions.i b/native/Functions.i
@@ -32,6 +32,9 @@ void arb_add_fmpz(arb_t z, const arb_t x, const fmpz_t y, slong prec);
 int fmpz_pow_fmpz(fmpz_t a, const fmpz_t b, const fmpz_t e);
 void arb_mul_fmpz(arb_t z, const arb_t x, const fmpz_t y, slong prec);
 void arb_sub_fmpz(arb_t z, const arb_t x, const fmpz_t y, slong prec);
+void fmpz_fac_ui(fmpz_t f, ulong n);
+void fmpz_rfac_ui(fmpz_t r, const fmpz_t x, ulong k);
+void fmpz_rfac_uiui(fmpz_t r, ulong x, ulong k);
 
 void fmpz_mul(fmpz_t f, const fmpz_t g, const fmpz_t h);
 void fmpz_divexact(fmpz_t f, const fmpz_t g, const fmpz_t h);

diff --git a/src/main/java/arb/Integer.java b/src/main/java/arb/Integer.java
@@ -51,6 +51,24 @@ public Real factorial(int bits, Real result)
     return result;
   }
 
+  public static Integer factorial(long n, Integer result)
+  {
+    arblib.fmpz_fac_ui(result.swigCPtr, n);
+    return result;
+  }
+
+  /**
+   * Calls this{@link #factorial(long, Integer)} putting the result into a newly
+   * instantiated Integer
+   * 
+   * @param n
+   * @return
+   */
+  public static Integer factorial(long n)
+  {
+    return factorial(n, new Integer());
+  }
+
   public static Real factorial(long n, int bits, Real result)
   {
     arblib.arb_fac_ui(result, n, bits);
@@ -265,6 +283,24 @@ public Integer pow(Integer operand, int bits, Integer result)
     return result;
   }
 
+  /**
+   * Shortcut for this{@link #div(Integer, int, Integer)} since it doesnt need
+   * bits
+   * 
+   * @param operand
+   * @param result
+   * @return
+   */
+  public Integer div(Integer operand, Integer result)
+  {
+    return div(operand, 0, result);
+  }
+
+  public Integer div(Integer operand)
+  {
+    return div(operand,this);
+  }
+
   /**
    * Division, rounded to integer
    * 

diff --git a/src/main/java/arb/arblib.java b/src/main/java/arb/arblib.java
@@ -49,6 +49,10 @@ public static void arb_sub_fmpz(Real z, Real x, long y, int prec) {
     arblibJNI.arb_sub_fmpz(Real.getCPtr(z), z, Real.getCPtr(x), x, y, prec);
   }
 
+  public static void fmpz_fac_ui(long f, long n) {
+    arblibJNI.fmpz_fac_ui(f, n);
+  }
+
   public static void fmpz_mul(long f, long g, long h) {
     arblibJNI.fmpz_mul(f, g, h);
   }

diff --git a/src/main/java/arb/arblibJNI.java b/src/main/java/arb/arblibJNI.java
@@ -19,6 +19,7 @@ public class arblibJNI {
   public final static native int fmpz_pow_fmpz(long jarg1, long jarg2, long jarg3);
   public final static native void arb_mul_fmpz(long jarg1, Real jarg1_, long jarg2, Real jarg2_, long jarg3, int jarg4);
   public final static native void arb_sub_fmpz(long jarg1, Real jarg1_, long jarg2, Real jarg2_, long jarg3, int jarg4);
+  public final static native void fmpz_fac_ui(long jarg1, long jarg2);
   public final static native void fmpz_mul(long jarg1, long jarg2, long jarg3);
   public final static native void fmpz_divexact(long jarg1, long jarg2, long jarg3);
   public final static native void fmpz_add(long jarg1, long jarg2, long jarg3);