4-12

#include <stdio.h>
int main(void)
{
 int child,men,women;
 for(men=0;men<=45;men++)
 for(women=0;women<=45;women++)
 for(child=0;child<=45;child++)
 if(men+women+child==45&&men*3+women*2+child*0.5==45)
 printf("men=%d,women=%d,child=%d\n",men,women,child);
 return 0;
}