Merge pull request dubesar#493 from gabsoares11/patch-1

ExtendedCountingSort

Author: dubesar

Sorting/ExtendedCountingSort.java

@@ -0,0 +1,52 @@
+public class ExtendedCountingSort {
+
+	public void sort(Integer[] array, int leftIndex, int rightIndex) {
+		if (array.length > 0) {
+			Integer biggest = biggestInt(array, leftIndex, rightIndex);
+			Integer smallest = smallestInt(array, leftIndex, rightIndex);
+
+			Integer[] c = new Integer[biggest - smallest + 1];
+			Integer[] b = new Integer[array.length];
+
+			Arrays.fill(c, 0);
+			
+			for (int i = leftIndex; i <= rightIndex; i++) {
+				c[array[i] - smallest] += 1;
+			}
+
+			for (int i = 1; i < c.length; i++) {
+				c[i] += c[i - 1];
+			}
+
+			for (int i = rightIndex; i >= leftIndex; i--) {
+				b[c[array[i] - smallest] - 1] = array[i];
+				c[array[i] - smallest] -= 1;
+			}
+
+			for (int i = 0; i < b.length; i++) {
+				array[i] = b[i];
+			}
+		}
+	}
+
+	private Integer smallestInt(Integer[] array, int leftIndex, int rightIndex) {
+		int m = array[leftIndex];
+
+		for (int i = leftIndex; i <= rightIndex ; i++) {
+			if (array[i] < m) { m = array[i]; }
+		}
+		
+		return m;
+	}
+
+	private Integer biggestInt(Integer[] array, int leftIndex, int rightIndex) {
+		int k = array[leftIndex];
+
+		for (int i = leftIndex; i <= rightIndex ; i++) {
+			if (array[i] > k) { k = array[i]; }
+		}
+    
+		return k;
+	}
+  
+}