Compilare: user.cpp: In function ‘int main()’: user.cpp:21:20: warning: unused variable ‘l1’ [-Wunused-variable] int i,j,n,m,len,l1,c1,l,c,sz; ^ user.cpp:21:23: warning: unused variable ‘c1’ [-Wunused-variable] int i,j,n,m,len,l1,c1,l,c,sz; ^ user.cpp:26:30: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d %d " ,&n,&m); ^