From 5fd2122c60998e543a800dbe096498d930063cf2 Mon Sep 17 00:00:00 2001
From: Sven Verdoolaege <skimo@kotnet.org>
Date: Fri, 18 Apr 2008 21:45:34 +0200
Subject: [PATCH] binomial.c: extract binomial and factorial from euler.cc

---
 Makefile.am |  2 ++
 binomial.c  | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 binomial.h  | 12 +++++++++++
 euler.cc    | 64 +--------------------------------------------------------
 4 files changed, 83 insertions(+), 63 deletions(-)
 create mode 100644 binomial.c
 create mode 100644 binomial.h

diff --git a/Makefile.am b/Makefile.am
index 640b270..6fa24d7 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -93,6 +93,8 @@ libbarvinok_core_la_SOURCES = \
     bernoulli.h \
     bfcounter.cc \
     bfcounter.h \
+    binomial.c \
+    binomial.h \
     conversion.cc \
     conversion.h \
     counter.cc \
diff --git a/binomial.c b/binomial.c
new file mode 100644
index 0000000..2a4467f
--- /dev/null
+++ b/binomial.c
@@ -0,0 +1,68 @@
+#include "binomial.h"
+
+struct binom {
+    Vector	**binom;
+    unsigned	size;
+    unsigned	n;
+};
+static struct binom binom;
+
+Value *binomial(unsigned n, unsigned k)
+{
+    int i, j;
+
+    if (n < binom.n)
+	return &binom.binom[n]->p[k];
+
+    if (n >= binom.size) {
+	int size = 3*(n + 5)/2;
+
+	binom.binom = (Vector **)realloc(binom.binom, size*sizeof(Vector *));
+	binom.size = size;
+    }
+    for (i = binom.n; i <= n; ++i) {
+	binom.binom[i] = Vector_Alloc(i+1);
+	if (!i)
+	    value_set_si(binom.binom[0]->p[0], 1);
+	else {
+	    value_set_si(binom.binom[i]->p[0], 1);
+	    value_set_si(binom.binom[i]->p[i], 1);
+	    for (j = 1; j < i; ++j)
+		value_addto(binom.binom[i]->p[j],
+			    binom.binom[i-1]->p[j-1], binom.binom[i-1]->p[j]);
+	}
+    }
+    binom.n = n+1;
+    return &binom.binom[n]->p[k];
+}
+
+struct fact {
+    Value 	*fact;
+    unsigned	size;
+    unsigned	n;
+};
+static struct fact fact;
+
+Value *factorial(unsigned n)
+{
+    int i;
+
+    if (n < fact.n)
+	return &fact.fact[n];
+
+    if (n >= fact.size) {
+	int size = 3*(n + 5)/2;
+
+	fact.fact = (Value *)realloc(fact.fact, size*sizeof(Value));
+	fact.size = size;
+    }
+    for (i = fact.n; i <= n; ++i) {
+	value_init(fact.fact[i]);
+	if (!i)
+	    value_set_si(fact.fact[0], 1);
+	else
+	    mpz_mul_ui(fact.fact[i], fact.fact[i-1], i);
+    }
+    fact.n = n+1;
+    return &fact.fact[n];
+}
diff --git a/binomial.h b/binomial.h
new file mode 100644
index 0000000..d93c0bb
--- /dev/null
+++ b/binomial.h
@@ -0,0 +1,12 @@
+#include <barvinok/polylib.h>
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+Value *binomial(unsigned n, unsigned k);
+Value *factorial(unsigned n);
+
+#if defined(__cplusplus)
+}
+#endif
diff --git a/euler.cc b/euler.cc
index 1f4f602..81874fb 100644
--- a/euler.cc
+++ b/euler.cc
@@ -7,6 +7,7 @@
 #include <barvinok/options.h>
 #include <barvinok/util.h>
 #include "bernoulli.h"
+#include "binomial.h"
 #include "conversion.h"
 #include "decomposer.h"
 #include "euler.h"
@@ -36,69 +37,6 @@ static unsigned total_degree(const evalue *e, unsigned nvar)
     return max_degree;
 }
 
-struct fact {
-    Value 	*fact;
-    unsigned	size;
-    unsigned	n;
-};
-struct fact fact;
-
-Value *factorial(unsigned n)
-{
-    if (n < fact.n)
-	return &fact.fact[n];
-
-    if (n >= fact.size) {
-	int size = 3*(n + 5)/2;
-
-	fact.fact = (Value *)realloc(fact.fact, size*sizeof(Value));
-	fact.size = size;
-    }
-    for (int i = fact.n; i <= n; ++i) {
-	value_init(fact.fact[i]);
-	if (!i)
-	    value_set_si(fact.fact[0], 1);
-	else
-	    mpz_mul_ui(fact.fact[i], fact.fact[i-1], i);
-    }
-    fact.n = n+1;
-    return &fact.fact[n];
-}
-
-struct binom {
-    Vector	**binom;
-    unsigned	size;
-    unsigned	n;
-};
-struct binom binom;
-
-Value *binomial(unsigned n, unsigned k)
-{
-    if (n < binom.n)
-	return &binom.binom[n]->p[k];
-
-    if (n >= binom.size) {
-	int size = 3*(n + 5)/2;
-
-	binom.binom = (Vector **)realloc(binom.binom, size*sizeof(Vector *));
-	binom.size = size;
-    }
-    for (int i = binom.n; i <= n; ++i) {
-	binom.binom[i] = Vector_Alloc(i+1);
-	if (!i)
-	    value_set_si(binom.binom[0]->p[0], 1);
-	else {
-	    value_set_si(binom.binom[i]->p[0], 1);
-	    value_set_si(binom.binom[i]->p[i], 1);
-	    for (int j = 1; j < i; ++j)
-		value_addto(binom.binom[i]->p[j],
-			    binom.binom[i-1]->p[j-1], binom.binom[i-1]->p[j]);
-	}
-    }
-    binom.n = n+1;
-    return &binom.binom[n]->p[k];
-}
-
 /*
  * Computes the coefficients of
  *
-- 
2.11.4.GIT