Compilare: user.cpp: In function ‘void PreprocessInput()’: user.cpp:143:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 1; i < val.size(); i++) ^ user.cpp:148:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 1; i < t.size(); i++) ^ user.cpp:155:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < vu.size(); i++) { ^ user.cpp:128:12: warning: unused variable ‘j’ [-Wunused-variable] int i, j, k; ^