Compilare: user.cpp: In function ‘int main()’: user.cpp:9:10: warning: unused variable ‘g’ [-Wunused-variable] FILE*g=fopen ("alee.out", "w"); ^ user.cpp:10:9: warning: unused variable ‘m’ [-Wunused-variable] int m , n ,l,c,i,j; ^ user.cpp:10:16: warning: unused variable ‘l’ [-Wunused-variable] int m , n ,l,c,i,j; ^ user.cpp:10:18: warning: unused variable ‘c’ [-Wunused-variable] int m , n ,l,c,i,j; ^ user.cpp:10:20: warning: unused variable ‘i’ [-Wunused-variable] int m , n ,l,c,i,j; ^ user.cpp:10:22: warning: unused variable ‘j’ [-Wunused-variable] int m , n ,l,c,i,j; ^ user.cpp:11:25: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf (f, "%d", &n); ^