Compilare: user.cpp: In function ‘int main()’: user.cpp:30:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (k=0;k<v[j].size();k++){ ^ user.cpp:39:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<v[0].size();i++){ ^ user.cpp:13:30: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d%d",&n,&m); ^ user.cpp:15:41: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d%d%d",&x,&y,&cst); ^