Page 99 - Computer Science Class 11 Without Functions
P. 99
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

