王道数据结构p149——8

#include
#include
typedef struct treenode{
	char data;
	struct treenode *lchild,*rchild;
}treenode,*tree;

//ABD##E##C##
void create(tree &t);
int findtwo(tree t);

int main(){
	tree T;
	//stack s;
	create(T);
	int a = findtwo(T);
	printf("%d",a);
	return 0;
} 
int findtwo(tree t){
	int i = 0;
	if(t){
		if(t->lchild && t->rchild){
			i++;
			printf("%c  ",t->data);
		} 
		i = i + findtwo(t->lchild);
		i = i + findtwo(t->rchild);
	}
	return i;
}

void create(tree &t){
	char c;
	c = getchar();
	if(c == '#') t = NULL;
	else{
		t = (treenode*)malloc(sizeof(treenode));
		t->data = c;
		t->lchild = NULL;
		t->rchild = NULL;
		create(t->lchild);
		create(t->rchild);
	}
}

注：树的建立参考了B站up 吸血小金鱼