Compilare: user.cpp: In function ‘int main()’: user.cpp:40:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (i < s.size()) ^ user.cpp:44:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i < s.size()) ^ user.cpp:30:30: warning: unused variable ‘len’ [-Wunused-variable] int current = 0, count = 0, len, i = 0, j = 0; ^