< Previous 　　　　　　　　　　　　　　　　 Next >

227. Basic Calculator II (Medium)

Implement a basic calculator to evaluate a simple expression string.

The expression string contains only non-negative integers, +, -, *, / operators and empty spaces . The integer division should truncate toward zero.

Example 1:

Input: "3+2*2"
Output: 7

Example 2:

Input: " 3/2 "
Output: 1

Example 3:

Input: " 3+5 / 2 "
Output: 5

Note:

• You may assume that the given expression is always valid.
• Do not use the eval built-in library function.

Related Topics

[String]

Similar Questions

1. Basic Calculator (Hard)
2. Expression Add Operators (Hard)
3. Basic Calculator III (Hard)