refactor RelabelBySorting

Author: cicirello

src/main/java/org/cicirello/sequences/distance/RelabelBySorting.java

@@ -1,6 +1,6 @@
 /*
  * JavaPermutationTools: A Java library for computation on permutations and sequences
- * Copyright 2005-2022 Vincent A. Cicirello, <https://www.cicirello.org/>.
+ * Copyright 2005-2023 Vincent A. Cicirello, <https://www.cicirello.org/>.
  *
  * This file is part of JavaPermutationTools (https://jpt.cicirello.org/).
  *
@@ -22,6 +22,7 @@
 package org.cicirello.sequences.distance;
 
 import java.util.Arrays;
+import java.util.Iterator;
 import java.util.List;
 
 /**
@@ -201,14 +202,53 @@ public int relabel(double[] s1, double[] s2, int[][] relabeling) {
   }
 
   @Override
-  @SuppressWarnings("unchecked")
   public int relabel(Object[] s1, Object[] s2, int[][] relabeling) {
-    return internalRelabel((Comparable[]) s1, (Comparable[]) s2, relabeling);
+    @SuppressWarnings("unchecked")
+    Comparable[] comp1 = (Comparable[]) s1;
+    @SuppressWarnings("unchecked")
+    Comparable[] comp2 = (Comparable[]) s2;
+    Comparable[] c1 = comp1.clone();
+    Arrays.sort(c1);
+    int[] labels = new int[c1.length];
+    int current = labels[0] = 0;
+    for (int i = 1; i < labels.length; i++) {
+      if (c1[i] != c1[i - 1]) current++;
+      labels[i] = current;
+    }
+
+    for (int i = 0; i < relabeling.length; i++) {
+      int j = Arrays.binarySearch(c1, comp1[i]);
+      relabeling[i][0] = labels[j];
+      j = Arrays.binarySearch(c1, comp2[i]);
+      validateElementIndex(j);
+      relabeling[i][1] = labels[j];
+    }
+    return current + 1;
   }
 
   @Override
-  @SuppressWarnings("unchecked")
   public <T> int relabel(List<T> s1, List<T> s2, int[][] relabeling) {
-    return internalRelabel((List<Comparable>) s1, (List<Comparable>) s2, relabeling);
+    @SuppressWarnings("unchecked")
+    List<Comparable> comp1 = (List<Comparable>) s1;
+    @SuppressWarnings("unchecked")
+    List<Comparable> comp2 = (List<Comparable>) s2;
+    Comparable[] c1 = comp1.toArray(new Comparable[comp1.size()]);
+    Arrays.sort(c1);
+    int[] labels = new int[c1.length];
+    int current = labels[0] = 0;
+    for (int i = 1; i < labels.length; i++) {
+      if (c1[i] != c1[i - 1]) current++;
+      labels[i] = current;
+    }
+    Iterator<Comparable> iter1 = comp1.iterator();
+    Iterator<Comparable> iter2 = comp2.iterator();
+    for (int i = 0; i < relabeling.length; i++) {
+      int j = Arrays.binarySearch(c1, iter1.next());
+      relabeling[i][0] = labels[j];
+      j = Arrays.binarySearch(c1, iter2.next());
+      validateElementIndex(j);
+      relabeling[i][1] = labels[j];
+    }
+    return current + 1;
   }
 }