Given an array of meeting time intervals intervals where intervals[i] = [starti, endi], return the minimum number of conference rooms required.
Implement a function that evaluates a basic arithmetic expression string containing non-negative integers, the binary operators +, -, *, /, and parentheses (). The expression may contain spaces.
- You may assume the input is a valid expression.
- Integer division should truncate toward zero (so
-3 / 2 = -1). - Return an integer result.
This prompt combines two classic interview problems: Meeting Rooms II and Basic Calculator. The first asks for the maximum number of overlapping intervals, typically solved with sorting plus a min-heap, sweep line, or two pointers. The second requires parsing and evaluating an arithmetic expression with operator precedence and parentheses, usually using stacks or recursive descent parsing. A key detail is that division must truncate toward zero.
