#20. Added and implemented counting sort with java.

Sorting Algorithms/Countsort.java

@@ -0,0 +1,47 @@
+public class CountingSort
+{
+    public static void sort(char arr[])
+    {
+        int n = arr.length;
+
+        // The output character array that will have sorted arr
+        char output[] = new char[n];
+
+        // Create a count array to store count of inidividul
+        // characters and initialize count array as 0
+        int count[] = new int[256];
+        for (int i = 0; i < 256; ++i)
+            count[i] = 0;
+
+        // store count of each character
+        for (int i=0; i<n; ++i)
+            ++count[arr[i]];
+
+        // Change count[i] so that count[i] now contains actual
+        // position of this character in output array
+        for (int i = 1; i <= 255; ++i)
+            count[i] += count[i-1];
+
+        // Build the output character array
+        for (int i = 0; i < n; ++i)
+        {
+            output[count[arr[i]] - 1] = arr[i];
+            --count[arr[i]];
+        }
+
+        // Copy the output array to arr, so that arr now
+        // contains sorted characters
+        for (int i = 0; i<n; ++i)
+            arr[i] = output[i];
+    }
+
+    public static void main(String args[])
+    {
+        char arr[] = {'h','a','c','k','t','o','b','e','r','f','e','s','t'};
+
+        sort(arr);
+        System.out.print("Sorted character array is ");
+        for (int i=0; i<arr.length; ++i)
+            System.out.print(arr[i]);
+    }
+}