#include <stdio.h>
void main ()
{int hcf(int, int);
int u,v,h,l;
scanf("%d,%d",&u,&v);
h=hcf(u,v);
printf("H.C.F=%d\n",h);
l=lcd(u,v,h);
printf("L.C.D=%d\n",l);
}

int hcf(intu,int v)
{int t,r;
 if (v>u)
 {t=u;u=v;v=t;}
while ((r=u%v)!=0)
{u=v;
v=r;}
return(v);
}

int lcd(int u,intv,inth)
{return(u*v/h);
}

l=lcd(u,v,h);
这个没有声明吧...

#include <stdio.h>
void main ()
{int hcf(int, int);
int lcd(int,int,int);
int u,v,h,l;
scanf("%d,%d",&u,&v);
h=hcf(u,v);
printf("H.C.F=%d\n",h);
l=lcd(u,v,h);
printf("L.C.D=%d\n",l);
}

int hcf(int u,int v)
{int t,r;
if (v>u)
{t=u;u=v;v=t;}
while ((r=u%v)!=0)
{u=v;
v=r;}
return(v);
}

int lcd(int u,int v,int h)
{return(u*v/h);
}