Challenge

Write a program that can perform mathematical operations on two or more numbers (up to four) like the calculator. 

Requirement

  • The calculator should support should addition, multiplication and subtraction operations (operators).
  • The input numbers (operands) would be positive whole numbers > 0 i.e. (1,2,3....) and < 9999
  • A minimum of two operands and one operator per expression will be provided as input.
  • A maximum of four operands with a maximum of three operators can be in the input expression.
  • An operator will not repeat again in the expression .e.g. 2+3+5 is not valid input as the operator (+) repeats twice in the expression. However, if your code can handle such expression it's even better.
  • Follow operator precedence rules while evaluating the expressions (multiplication,  addition, subtraction).
  • All input will be provided correctly, so data validation is not expected.

Test cases

Based on the operator (+ , - , * ) perform the correct mathematical operation on the operands. 

Test cases

No.
Expression
(Input)
Result
(Output)
Explanation
1
5+1
6

2
10*2
20

3
15+2-3
10

4
20*2+5
45
Perform multiplication first, then add.
5
20-10*2
10Perform multiplication first, then add.
6
20-10*2+5
5Perform the multiplication first, followed by addition and then subtraction.

Instructions

  • Accept the mathematical expression to evaluate as a single input argument to the program.
  • Evaluate the input express and display the result.

Next Level

If you are able to solve this challenge, move up next level of Advance Line Expression Calculator.