Compilare: user.c: In function ‘suma’: user.c:27: warning: statement with no effect user.c:28: warning: statement with no effect user.c: In function ‘main’: user.c:31: warning: unused variable ‘y2’ user.c:31: warning: unused variable ‘y1’ user.c:31: warning: unused variable ‘x2’ user.c:31: warning: unused variable ‘x1’ user.c:33: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result user.c:37: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result user.c: In function ‘suma’: user.c:29: warning: control reaches end of non-void function