Compilare: user.cpp: In function ‘void bt(int)’: user.cpp:12:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<l[v[k-1]].size()&&ok==0;i++) ^ user.cpp:11:14: warning: unused variable ‘j’ [-Wunused-variable] {int i,z,j; ^ user.cpp: In function ‘int main()’: user.cpp:60:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<l[x].size()&&ok==0;j++) ^ user.cpp:40:28: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d %d",&n,&m); ^ user.cpp:43:32: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d %d",&x,&y); ^ user.cpp:48:22: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&q); ^ user.cpp:51:32: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d %d",&x,&y); ^