Added a quicksort test case

git-svn-id: http://picoc.googlecode.com/svn/trunk@311 21eae674-98b7-11dd-bd71-f92a316d2d60

tests/25_quicksort.c

@@ -0,0 +1,75 @@
+int array[16];
+
+array[0] = 62;
+array[1] = 83;
+array[2] = 4;
+array[3] = 89;
+array[4] = 36;
+array[5] = 21;
+array[6] = 74;
+array[7] = 37;
+array[8] = 65;
+array[9] = 33;
+array[10] = 96;
+array[11] = 38;
+array[12] = 53;
+array[13] = 16;
+array[14] = 74;
+array[15] = 55;
+
+//Swap integer values by array indexes
+void swap(int a, int b)
+{
+    int tmp  = array[a];
+    array[a] = array[b];
+    array[b] = tmp;
+}
+
+//Partition the array into two halves and return the
+//index about which the array is partitioned
+int partition(int left, int right)
+{
+    int pivotIndex = left;
+    int pivotValue = array[pivotIndex];
+    int index = left;
+    int i;
+ 
+    swap(pivotIndex, right);
+    for(i = left; i < right; i++)
+    {
+        if(array[i] < pivotValue)
+        {
+            swap(array, i, index);
+            index += 1;
+        }
+    }
+    swap(right, index);
+ 
+    return index;
+}
+ 
+//Quicksort the array
+void quicksort(int left, int right)
+{
+    if(left >= right)
+        return;
+ 
+    int index = partition(left, right);
+    quicksort(left, index - 1);
+    quicksort(index + 1, right);
+}
+ 
+int i;
+
+for (i = 0; i < 16; i++)
+    printf("%d ", array[i]);
+
+printf("\n");
+
+//quicksort(0, 15);
+
+for (i = 0; i < 16; i++)
+    printf("%d ", array[i]);
+
+printf("\n");
+