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Basic Calculator leetcode: basic_calculator
Implement a basic calculator to evaluate a simple expression string.
The expression string may contain open (
and closing parentheses )
, the plus +
or minus sign -
, non-negative integers and empty spaces .
Example1:
Input: "1 + 1"
Output: 2
Example2:
Input: " 2-1 + 2 "
Output: 3
Example3:
Input: "(1+(4+5+2)-3)+(6+8)"
Output: 23
Note
-
You may assume that the given expression is always valid.
-
Do not use the
eval
built-in library function.
Functionsยง
- calculate
- Solutions