Compilare: user.cpp: In function ‘bool ok(int)’: user.cpp:12:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j,x,y; ^ user.cpp: In function ‘int main()’: user.cpp:34:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j; ^ user.cpp:35:28: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d %d",&k,&n); ^ user.cpp:37:33: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&v[i]); ^