Linear search of an array

• A linear search of an array looks at each element starting with first

  Linear_search_of_an_array
   Set max_num_elements to required value
   Set element_found to false
   Set index to 1
  
   DOWHILE(NOT element_found)AND(index <= max_num_elements)
        IF array(index)= input_value THEN
          Set element_found to true
        ELSE
          index = index + 1
        ENDIF
   ENDDO
  
   IF element_found THEN
       Print array (index)
   ELSE
       Print ‘value not found’, input_value
   ENDIF
  END
  

Binary search of an array

• faster than linear search for arrays with > 25 elements
• first, sort elements into ascending sequence
• next, locate the middle element
• then determine if your element is in the first half or second
• repeat the process with the selected half of the array

`` Binary_search_of_an_array

Set element_found to false Set low_element to 1 Set high_element to max_num_elements

DOWHILE (NOT element_found) AND(low_element <= high_element) index = (low_element + high_element)/2

   IF input_value = array (index)THEN
      Set element_found to true
   ELSE
      IF input_value < array (index)THEN
          high_element = index – 1
      ELSE
          low_element = index + 1
      ENDIF
   ENDIF

ENDDO

IF element_found THEN Print array (index) ELSE Print ‘value not found’, input_value ENDIF END

####Writing out contents of an array
* use DO loop
* start with first element
* write each element until done

Write_values_of_array DO index = 1 to number_of_elements Print array(index) ENDDO END ```