Add tree printing support (left->right)

print_helper.c

@@ -45,3 +45,16 @@ void print_char(unsigned char c)
 		break;
 	}
 }
+
+void print_tree(struct tree *r,int l)
+{
+	int i;
+	if(!r) return ;
+	print_tree(r->right,l+1);
+	for(i=0;i<l;++i)
+		printf(" ");
+	print_char(r->ch);
+	print_tree(r->left,l+1);
+
+
+}

print_helper.h

@@ -21,5 +21,6 @@ void __printb(void *value, size_t size);
 })
 
 void print_char(unsigned char c);
+void print_tree(struct tree *r,int l);
 
 #endif /* _PRINT_HELPER_H_ */