If we have sent at least ~K~ consecutive messages, then SSS...SS (which is of length ~K~) will appear as a substring of the input string.

Thus it suffices to check if this string is contained.

Time Complexity: ~\mathcal O(MK)~, where ~M~ is the total number of messages sent.

This can be optimized to ~\mathcal O(M + K)~ by finding the number of consecutive Ss for each prefix. Let ~P[i]~ be the smallest index ~j~ such that ~S[j] = S[j + 1] = S[j+2] = \cdots = S[i-1] = S[i] =~ S. Then ~P[i+1] = P[i]+1~ if ~S[i] =~ S, and 0 otherwise. Print Spamming if ~P[i] \geq K~ for any ~i \leq N~, and All good otherwise.