C. Verify godebach's Conjecture

# Include <math. h> Int Checkprimer ( Double A ){ //  Verify whether it is a prime number  Unsigned  Long  I, asqrt; asqrt = (Unsigned Long  ) SQRT ();  For (I = 2 ; I <= asqrt; I ++ ){  If (( Int ) A % I = 0  )  Return   0  ;}  Return   1  ;}  Int Checktruth (unsigned Long A, unsigned Long * Numbera, unsigned Long * Numberb) {unsigned  Long I, half =/2  ;  For (I = 3 ; I  2  ){  If (Checkprimer (( Double ) I) & checkprimer (( Double ) (- I ))){ * Numbera = I; * Numberb =- I;  Return   1 ;}}  Return   0  ;} Test. h file # include <Stdio. h> # Include <Math. h> # Include  "  Test1.h  "  Void  Main () {unsigned  Long  A, P1, P2;  Do  {Printf ( "  Enter an even number \ n not less than 6  "  ); Scanf (  "  % Lu  " ,& A );  If (A> = 6 & A % 2 = 0  ){  If (Checktruth (A, & P1 ,& P2) {printf ( "  OK, % d \ n  "  , P1, P2 );}  Else  {Printf (  "  Sorry!  "  );}}}  While (! = 0  );  Return  ;} Test. c file 

An even number greater than 6 can be composed of two prime numbers.

Running result: