add sorted

Signed-off-by: Mattias Andrée <maandree@operamail.com>

1 files changed, 87 insertions, 0 deletions

diff --git a/src/algorithms/arrays/Sorted.java b/src/algorithms/arrays/Sorted.java
new file mode 100644
index 0000000..c99ada5
--- /dev/null
+++ b/src/algorithms/arrays/Sorted.java
@@ -0,0 +1,87 @@
+/**
+ * Copyright © 2014  Mattias Andrée (maandree@member.fsf.org)
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 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 Affero General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package algorithms.arrays;
+
+import java.util.*;
+
+
+/**
+ * Class for checking whether an array is sorted and in which order it is sorted
+ */
+public class Sorted
+{
+    /**
+     * The array is not sorted
+     */
+    public static final int UNORDERED = 0;
+    
+    /**
+     * The array is sorted in ascending (normal) order
+     */
+    public static final int ASCENDING_ORDER = 1;
+    
+    /**
+     * The array is sorted in descending (reverse normal) order
+     */
+    public static final int DESCENDING_ORDER = 2;
+    
+    /**
+     * All elements in the array are mutually equal or the array contains less than two elements.<br>
+     * This is the bitwise OR of {@link ASCENDING_ORDER} and {@link DESCENDING_ORDER}.
+     */
+    public static final int FLAT = 3;
+    
+    
+    
+£>for T in boolean char byte short int long float double T T+; do . src/comparable
+    /**
+     * Gets whether an array is sorted and in which order it is sorted
+     *
+     * @param   items  The items to check if they are ordered
+     * @return         {@link #UNORDERED}, {@link #ASCENDING_ORDER}, {@link #DESCENDING_ORDER} or {@link #FLAT}
+     */
+    public static £(fun "int" "isSorted" "${T}[] items")
+    {
+	if (items.length == 0)
+	    return FLAT;
+        
+	£{T} last = items[0], cur;
+	int order = FLAT;
+        
+	for (int i = 1, n = items.length; i < n; i++)
+	{
+	    cur = items[i];
+	    if (£(less "last" "cur"))
+	    {
+		if (order == FLAT)
+		    order = ASCENDING_ORDER;
+		else if (order == DESCENDING_ORDER)
+		    return UNORDERED;
+	    }
+	    else if (£(greater "last" "cur"))
+		if (order == FLAT)
+		    order = DESCENDING_ORDER;
+		else if (order == ASCENDING_ORDER)
+		    return UNORDERED;
+	    last = cur;
+	}
+        
+	return order;
+    }
+£>done
+}
+