Compilare: user.cpp: In function ‘int main()’: user.cpp:23:23: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(IN,"%d",&N); ^ user.cpp:27:32: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(IN,"%d%d",&A,&B); ^ user.cpp:38:16: warning: iteration 54u invokes undefined behavior [-Waggressive-loop-optimizations] if(fr[i]>0) ^ user.cpp:37:5: note: containing loop for(int i=1;i<MaxN;i++) ^