目前我的代码允许我搜索特定的节点,我想编辑它,以便我可以在数字范围内搜索。例如,我有一份苹果的价目表,我想把所有价格在2美元到4美元之间的苹果添加到列表/字典中。
这是我当前的代码
def valueOf(self, key):
node = self._bstSearch(self._root, key)
assert node is not None, "Invalid map key."
return node.value
def _bstSearch(self, subtree, target):
if subtree is None:
return None
elif target < subtree.key:
return self._bstSearch( subtree.left, target)
elif target > subtree.key:
return self._bstSearch(subtree.right, target)
else:
return subtree
我想我应该编辑目标,将其从单个项目搜索更改为范围项目搜索,但我不是100%确定如何
使用递归序遍历:
def range(self, a, b):
return self._traverse_range(self._root, a, b)
def _traverse_range(self, subtree, a, b, cumresult=None):
if subtree is None:
return
# Cumulative variable.
if cumresult is None:
cumresult = []
# Traverse LEFT subtree if it is possible to find values in required range there.
if subtree.key > a:
self._traverse_range(subtree.left, a, b, cumresult)
# Push VALUE if it is in our range.
if a <= subtree.key <= b: # Change to strict "< b" to act like python's range
cumresult.append(subtree.key)
# Traverse RIGHT subtree if it is possible to find values in required range there.
if subtree.key < b:
self._traverse_range(subtree.right, a, b, cumresult)
return cumresult