HackerRank Problem #15

Mars Exploration

Problem

A space explorer’s ship crashed on Mars! They send a series of SOS messages to Earth for help.

Letters in some of the SOS messages are altered by cosmic radiation during transmission. Given the signal received by Earth as a string, s, determine how many letters of the SOS message have been changed by radiation.

Example

s = ‘SOSTOT’

The original message was SOSSOS. Two of the message's characters were changed in transit.

Function Description

Complete the marsExploration function in the editor below.

marsExploration has the following parameter(s):

• string s: the string as received on Earth

Returns

• int: the number of letters changed during transmission

Input Format

There is one line of input: a single string, s.

Constraints

• 1 ≤ length of s ≤ 99
• length of s modulo 3 = 0
• s will contain only uppercase English letters, ascii[A — Z].

Sample 0

Sample Input 0

SOSSPSSQSSOR

Sample Output 0

3