Compilare: user.cpp: In function ‘int main()’: user.cpp:60:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1;i < sorted.size();i ++) { ~~^~~~~~~~~~~~~~~ user.cpp:62:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(pos < sorted[i].size() && pos < sorted[i-1].size() && sorted[i][pos] == sorted[i-1][pos]) ~~~~^~~~~~~~~~~~~~~~~~ user.cpp:62:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(pos < sorted[i].size() && pos < sorted[i-1].size() && sorted[i][pos] == sorted[i-1][pos]) ~~~~^~~~~~~~~~~~~~~~~~~~ user.cpp:51:23: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(v, NMAX, in); ^