Compilare: user.cpp: In function ‘int main()’: user.cpp:123:13: warning: unused variable ‘i’ [-Wunused-variable] int n,m,i,j; ^ user.cpp:123:15: warning: unused variable ‘j’ [-Wunused-variable] int n,m,i,j; ^ user.cpp:124:30: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d %d",&n,&m); ^