Compilare: user.cpp: In function ‘int main()’: user.cpp:11:19: warning: unused variable ‘j’ [-Wunused-variable] int n,m,x,y,i,j; ^ user.cpp:12:28: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d%d",&n,&m); ^ user.cpp:20:32: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d%d",&x,&y); ^