Compilare: user.cpp: In function ‘int main()’: user.cpp:26:11: warning: unused variable ‘A’ [-Wunused-variable] point A = { 0, 1 }; ^ user.cpp:27:11: warning: unused variable ‘B’ [-Wunused-variable] point B = { 1, 1 }; ^ user.cpp:28:11: warning: unused variable ‘C’ [-Wunused-variable] point C = { 1, 2 }; ^ user.cpp:31:35: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf( input_file, "%d", &N ); ^ user.cpp:34:56: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf( input_file, "%d %d", &P[i].x, &P[i].y ); ^ user.cpp: In function ‘int det(point, point, point)’: user.cpp:15:1: warning: control reaches end of non-void function [-Wreturn-type] } ^