Compilare: main.cpp: In function 'void euler(int, int)': main.cpp:57:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<v[a].size(); i++) ~^~~~~~~~~~~~ main.cpp: In function 'void read()': main.cpp:29:22: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&n); ^ main.cpp:35:38: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d %d",&x[i],&y[i]); ^