Page 111 - Computer Science V2.0 Class 11

The flowchart for the above pseudocode is given below (Fig 4.8):

Start

input n

False True
n % 2 == 0

print "Odd" print "Even"

Stop

Fig 4.8: Flowchart to check whether the user entered number is even or odd
Validating User's Key on a Mobile: All of us have used smartphones. A smartphone provides a simple security feature
that guards against unauthorized use of the smartphone. When a user buys a smartphone, they can set a secret key (also
called a password) of their choice. The phone gets automatically locked when not in use for some time (typically a few
seconds to a minute, as per the user settings). To use the smartphone again, the user needs to enter the password. The
input entered by the user (let us call it userkey) is matched against the password stored in the smartphone's memory. As
a user might enter a wrong key accidentally, the smartphone allows a certain number (typically five) of failed attempts.
After the allowable limit on failed attempts, to avoid repeated failed attempts in quick succession, the smartphone gets
locked for a longer period (say, one minute). Below we develop a flowchart for unlocking the smartphone.

Start

Counter = 0

input userkey

False
counter <= 5

True

Yes
userkey ==
password

No
Increment counter by 1

Phone locked for
longer duration Phone Unlocked!

Stop

Fig 4.9: Flowchart to unlock a smartphone. It validates the user input (userkey) against the password saved in a smartphone.

Problem Solving 97