Swipe Details-Simple Scenario

I have a table where Swipe IN ans Swipe OUT details are recorded.Suppose,If I need to find
How many employees are inside/outside the campus?

Assumption:For every IN,there is an OUT strictly.


CREATE TABLE SWIPE
(
BADGEID INTEGER,
SWIPE_TS TIMESTAMP(0),
ACTN VARCHAR2(3)
);

INSERT INTO SWIPE VALUES(1,CURRENT_TIMESTAMP(0)- INTERVAL '5' MINUTE,'IN');
INSERT INTO SWIPE VALUES(1,CURRENT_TIMESTAMP(0),'OUT');
INSERT INTO SWIPE VALUES(2,CURRENT_TIMESTAMP(0)- INTERVAL '5' MINUTE,'IN');
INSERT INTO SWIPE VALUES(3,CURRENT_TIMESTAMP(0)- INTERVAL '5' MINUTE,'IN');
INSERT INTO SWIPE VALUES(3,CURRENT_TIMESTAMP(0),'OUT');
INSERT INTO SWIPE VALUES(4,CURRENT_TIMESTAMP(0)- INTERVAL '5' MINUTE,'IN');

SELECT * FROM SWIPE;

Approach 1:

Inside Campus:


SELECT BADGEID
FROM SWIPE
GROUP BY BADGEID
HAVING MOD(COUNT(*),2)=1

Outside Campus:


SELECT BADGEID
FROM SWIPE
GROUP BY BADGEID
HAVING MOD(COUNT(*),2)=0