1 files changed, 103 insertions, 0 deletions
diff --git a/tdemid/randomlist.cpp b/tdemid/randomlist.cpp
new file mode 100644
index 00000000..f26b8cfc
--- /dev/null
+++ b/tdemid/randomlist.cpp
@@ -0,0 +1,103 @@
+/**************************************************************************
+
+    randomlist.cpp  - Some "random functions" :-)
+    Copyright (C) 1997,98  Antonio Larrosa Jimenez
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
+    Send comments and bug fixes to larrosa@kde.org
+    or to Antonio Larrosa, Rio Arnoya, 10 5B, 29006 Malaga, Spain
+
+***************************************************************************/
+#include "randomlist.h"
+#include <stdlib.h>
+#include <stdio.h>
+
+#define RAND_UNIFORM (double)rand()/(double)RAND_MAX
+
+int random_discrete(double *distrib,int n)
+{
+    int i=0;
+    double g=0.0;
+    double z=0.0;
+    while ((z==0.0)||(z==1.0)) z=RAND_UNIFORM;
+    while ((g<z)&&(i<n))
+    {
+        g+=distrib[i];
+        i++;
+    };
+    return i-1;
+}
+
+double *generate_discrete_uniform_distrib(int n)
+{
+    double *distrib=new double[n];
+
+    for (int i=0;i<n;i++)
+        distrib[i]=1.0/(double)n;
+
+    return distrib;
+}
+
+void remove_lmn_from_discrete_distrib(int k,double *distrib,int n,int used=0)
+{
+    int i;
+    if (used==0)  //guess how many values of the v.a. are strictly positive
+    {
+        for (i=0;i<n;i++) if (distrib[i]>0) used++;
+    };
+    used--; // k will no longer be used :-)
+    if (used==0) return;
+    double piece=distrib[k]/(double)used;
+    distrib[k]=0.0;
+    for (i=0;i<n;i++) if (distrib[i]>0) distrib[i]+=piece;
+}
+
+void show_distrib(double *distrib,int n)
+{
+    printf("(");
+    for (int j=0;j<n;j++) printf("%g,",distrib[j]);
+    printf(")\n");
+}
+
+int *generate_random_list(int n)
+{
+    if (n==0) return NULL;
+    int *list=new int[n];
+    double *distrib=generate_discrete_uniform_distrib(n);
+    int used=n;
+    int x;
+    int i=1;
+    while (used>0)
+    {
+        x=random_discrete(distrib,n);
+        list[x]=i;
+        i++;
+        remove_lmn_from_discrete_distrib(x,distrib,n,used);
+        used--;
+    };
+    delete distrib;
+    
+    return list;
+}
+
+int *generate_list(int n)
+{
+    int *list=new int[n];
+    for (int i=0;i<n;i++)
+        list[i]=i+1;
+
+    return list;
+}