add documented jump search algorithm

dsalglib/include/jumpsearch.h

@@ -0,0 +1,45 @@
+#ifndef DSALGLIB_KMPSEARCH_H
+#define DSALGLIB_KMPSEARCH_H
+
+#include "array.h"
+
+namespace dsa
+{
+    template<typename type>
+	long long int jumpsearch( array<type> arr, type x)
+	{
+		// Finding block size to be jumped
+		long long int n = arr.size(); 
+		long long int step = sqrt(n);
+
+		// Finding the block where element is
+		// present (if it is present)
+		long long int prev = 0;
+		while (arr[min(step, n)-1] < x)
+		{
+			prev = step;
+			step += sqrt(n);
+			if (prev >= n)
+				return -1;
+		}
+
+		// Doing a linear search for x in block
+		// beginning with prev.
+		while (arr[prev] < x)
+		{
+			prev++;
+
+			// If we reached next block or end of
+			// array, element is not present.
+			if (prev == min(step, n))
+				return -1;
+		}
+		// If element is found
+		if (arr[prev] == x)
+			return prev;
+
+		return -1;
+	}
+
+}
+#endif //DSALGLIB_KMPSEARCH_H