Compilare: user.cpp: In function ‘bool is_good(int)’: user.cpp:47:19: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if(u) ^ user.cpp: In function ‘int main()’: user.cpp:5:11: warning: unused variable ‘first’ [-Wunused-variable] #define x first ^ user.cpp:61:11: note: in expansion of macro ‘x’ int i,x,y,D,st,dr,mid; ^ user.cpp:6:11: warning: unused variable ‘second’ [-Wunused-variable] #define y second ^ user.cpp:61:13: note: in expansion of macro ‘y’ int i,x,y,D,st,dr,mid; ^ user.cpp:64:24: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&N); ^ user.cpp:67:54: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d %d %d %d",&A.x,&A.y,&B.x,&B.y); ^