Short Problem Definition:
Sami’s spaceship crashed on Mars! She sends a series of SOS
messages to Earth for help.
Link
Complexity:
time complexity is O(N)
space complexity is O(1)
Execution:
We know that the message is basically a lot of concatenated SOS strings. There is no magic to this one.
Solution:
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S = raw_input ().strip() errors = 0 for i in xrange ( len (S)): if i % 3 = = 0 and S[i] ! = 'S' : errors + = 1 if i % 3 = = 1 and S[i] ! = 'O' : errors + = 1 if i % 3 = = 2 and S[i] ! = 'S' : errors + = 1 print errors 