哥德巴赫猜想：将一个奇数拆分成三个素数之和。
要求：素数按从小到大且是最小的两个素数与另一个素数组合
如：15=2+2+11
15=3+5+7等，程序要求只输出前一种拆分方法。
样例： 
输入：15
输出：15=2+2+11
 
要求：用子程序实现判素数


我编的是

 var m,n,i,j:integer;
 function ss(x:integer):integer;
 var k,f:integer;
 begin
     f:=1;
     for k:=2 to trunc(sqrt(x)) do
        if x mod k=0 then begin
                                f:=0;
                                break;
                          end;
     ss:=f;
 end;
 begin
        read(n);
        m:=n;
        for i:=2 to m-1 do
            if ss(i)+ss(m-i)=1 then if ss(i)=0 then
                                        begin
                                                for j:=2 to i-1 do
                                                    if ss(j)+ss(i-j)=2 then
                                                        begin
                                                              writeln(n,'=',m-i,'+',j,'+',i-j);
                                                              exit;
                                                        end;
                                        end
                                     else
                                         begin
                                                for j:=2 to m-i-1 do
                                                    if ss(j)+ss(m-i-j)=2 then
                                                        begin
                                                              writeln(n,'=',i,'+',j,'+',m-i-j);
                                                              exit;
                                                        end;
                                         end;
 end.




答案有的对有的错，请大虾在原题上修改并跟帖发送，菜鸟感谢不已！！！