eval()
when there are this kind of exploring " "/+/- question, we do dfs. We can use replace() to replace the " " with "" and then use eval() which automatically evaluates an expression into an integer for us
when there are this kind of exploring " "/+/- question, we do dfs. We can use replace() to replace the " " with "" and then use eval() which automatically evaluates an expression into an integer for us
