Compilare: user.cpp: In function ‘void PrefixFunction()’: user.cpp:28:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 1; j < a[i].size(); ++j) ^ user.cpp: In function ‘bool KMP(int, int)’: user.cpp:41:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < a[s1].size(); ++i) ^ user.cpp:47:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (k == a[s2].size() - 1) ^ user.cpp: In function ‘void BuildCost()’: user.cpp:60:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < A[s1].size(); ++i) ^ user.cpp:67:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i == A[s1].size() - 1) ^