Adding splay and binary tree code

diff --git a/include/splay.h b/include/splay.h
new file mode 100644 (file)
index 0000000..00ad460
--- /dev/null
+++ b/include/splay.h
@@ -0,0 +1,15 @@
+
+typedef struct _splay_node {
+       void *data;
+       struct _splay_node *left;
+       struct _splay_node *right;
+} splayNode;
+
+typedef int (*SPCMP) _PARAMS((const void *, splayNode *));
+
+extern int splayLastResult;
+
+splayNode *splay_insert _PARAMS((void *, splayNode *, SPCMP));
+splayNode *splay_splay _PARAMS((const void *, splayNode *, SPCMP));
+void splay_destroy _PARAMS((splayNode *, void (*) _PARAMS((void *))));
+

diff --git a/lib/Makefile.in b/lib/Makefile.in
index 820ce4aa70ab8ef586a8878b5f17b8d035647703..d16f070c6375719c373a455164e62f9d76ddc5dc 100644 (file)
--- a/lib/Makefile.in
+++ b/lib/Makefile.in
@@ -3,7 +3,7 @@
 #
 #  Darren Hardy, hardy@cs.colorado.edu, April 1994
 #
-#  $Id: Makefile.in,v 1.20 1996/11/25 02:38:20 wessels Exp $
+#  $Id: Makefile.in,v 1.21 1997/02/20 21:04:07 wessels Exp $
 #
 prefix         = @prefix@
 srcdir         = @srcdir@
@@ -29,6 +29,8 @@ UTILOBJS      = rfc1123.o \
                  getfullhostname.o \
                  base64.o \
                  uudecode.o \
+                 tree.o \
+                 splay.o \
                  $(LIBOBJS)
 REGEXOBJS      = GNUregex.o
 LIBS           = libmiscutil.a @LIBREGEX@

diff --git a/lib/splay.c b/lib/splay.c
new file mode 100644 (file)
index 0000000..167e065
--- /dev/null
+++ b/lib/splay.c
@@ -0,0 +1,157 @@
+
+#include "config.h"
+
+#if HAVE_STDIO_H
+#include <stdio.h>
+#endif
+#if HAVE_STDLIB_H
+#include <stdlib.h>
+#endif
+#if HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+#include "ansiproto.h"
+#include "splay.h"
+#include "util.h"
+
+int splayLastResult = 0;
+
+splayNode *
+splay_insert (void *data, splayNode *top, SPCMP compare)
+{
+    splayNode *new = xcalloc(sizeof(splayNode), 1);
+    new->data = data;
+    if (top == NULL) {
+        new->left = new->right = NULL;
+        return new;
+    }
+    top = splay_splay(data, top, compare);
+    if (splayLastResult < 0) {
+        new->left = top->left;
+        new->right = top;
+        top->left = NULL;
+        return new;
+    } else if (splayLastResult > 0) {
+        new->right = top->right;
+        new->left = top;
+        top->right = NULL;
+        return new;
+    } else {
+       /* duplicate entry */
+        free(new);
+        return top;
+    }
+}
+
+splayNode *
+splay_splay (const void *data, splayNode *top, SPCMP compare)
+{
+    splayNode N;
+    splayNode *l;
+    splayNode *r;
+    splayNode *y;
+    if (top == NULL)
+        return top;
+    N.left = N.right = NULL;
+    l = r = &N;
+
+    for (;;) {
+        splayLastResult = compare(data, top);
+        if (splayLastResult < 0) {
+            if (top->left == NULL)
+                break;
+            if ((splayLastResult = compare(data, top->left)) < 0) {
+                y = top->left;    /* rotate right */
+                top->left = y->right;
+                y->right = top;
+                top = y;
+                if (top->left == NULL)
+                    break;
+            }
+            r->left = top;        /* link right */
+            r = top;
+            top = top->left;
+        } else if (splayLastResult > 0) {
+            if (top->right == NULL)
+                break;
+            if ((splayLastResult = compare(data, top->right)) > 0) {
+                y = top->right;   /* rotate left */
+                top->right = y->left;
+                y->left = top;
+                top = y;
+                if (top->right == NULL)
+                    break;
+            }
+            l->right = top;       /* link left */
+            l = top;
+            top = top->right;
+        } else {
+            break;
+        }
+    }
+    l->right = top->left;         /* assemble */
+    r->left = top->right;
+    top->left = N.right;
+    top->right = N.left;
+    return top;
+}
+
+void
+splay_destroy(splayNode *top, void (*free_func) _PARAMS((void *)))
+{
+       if (top->left)
+               splay_destroy(top->left, free_func);
+       if (top->right)
+               splay_destroy(top->right, free_func);
+       free_func(top->data);
+       xfree(top);
+}
+
+
+#ifdef DRIVER
+
+void
+splay_print(splayNode *top, void (*printfunc)())
+{
+       if (top == NULL)
+               return;
+       splay_print(top->left, printfunc);
+       printfunc(top->data);
+       splay_print(top->right, printfunc);
+}
+
+typedef struct {
+       int i;
+} intnode;
+
+int
+compareint (void *a, splayNode *n)
+{
+       intnode *A = a;
+       intnode *B = n->data;
+       return A->i - B->i;
+}
+
+void
+printint (void *a)
+{
+       intnode *A = a;
+       printf ("%d\n", A->i);
+}
+
+main(int argc, char *argv[])
+{
+       int i;
+       intnode *I;
+       splayNode *top = NULL;
+       srandom(time(NULL));
+       for (i=0; i< 100; i++) {
+               I = xcalloc (sizeof(intnode), 1);
+               I->i = random();
+               top = splay_insert(I, top, compareint);
+       }
+       splay_print (top, printint);
+       return 0;
+}
+#endif