class BrowserHistory:
def __init__(self, homepage: str):
self.urls = []
self.index = -1
self.lastIndex = -1
self.visit(homepage)
def visit(self, url: str) -> None:
self.index += 1
if self.index < len(self.urls):
self.urls[self.index] = url
else:
self.urls.append(url)
self.lastIndex = self.index
def back(self, steps: int) -> str:
self.index = max(0, self.index - steps)
return self.urls[self.index]
def forward(self, steps: int) -> str:
self.index = min(self.lastIndex, self.index + steps)
return self.urls[self.index]