Compilare: main.cpp: In function 'int main()': main.cpp:127:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (unsigned int j=1;j<=sz;++j) G[i].push_back(vtest[j]); ~^~~~ main.cpp: In function 'int BF(int, int)': main.cpp:66:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ main.cpp: In function 'int main()': main.cpp:70:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pirati.in","r",stdin); ^ main.cpp:71:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pirati.out","w",stdout); ^ main.cpp:74:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d\n",&N,&M,&Q); ^ main.cpp:77:30: warning: ignoring return value of 'char* fgets(char*, int, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fgets(matr[i]+1,1005,stdin); ^ main.cpp:132:36: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d",&x1,&y1,&x2,&y2); ^