START

Input a number "n"

Is Input "n" a positive integer

Display "INVALID INPUT"

Initialize a SEEN SET

Initialize CURRENT NUMBER and set it as the INPUT "n"

Is CURRENT NUMBER Equal to 1

Display "INPUT is a Happy Number"

Is CURRENT NUMBER in SEEN SET

Add CURRENT NUMBER to SEEN SET

Display "INPUT is not a Happy Number"

Replace CURRENT NUMBER with the sum of square of digits

END

Q35