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Problem 3. Calculator

Description

Class Exercise 2

Implements a basic calculator. The program reads two numbers and an operator from the user and then performs a mathematical operation based on the provided operator. The supported operators are '+', '-', '*', and '/'. The program then prints the result of the operation. This is an example in the class.

Then modify the program to make it run repeatedly in a loop, allowing the user to perform multiple calculations without having to restart the program and asking the user whether he wants to continue to use the calculator or quit the calculator.

Input format

• Each line contains a real number $x_i$, an character $op_i$ and a real number $y_i$, separated by a space. The following line contains a character y or n.
  • For 100% cases, $|x_i|\leq 100$ and $|y_i|\leq 100$. Division by zero won't happen.
• The program stops when n is read from the input.

Output format

• For each calculation, if $op_i$ is a supported operator, output the result in the format xxx p yyy == zzz, where xxx and yyy are replaced with $x_i$ and $y_i$ respectively, p is replaced with the operator $op_i$, and zzz is replaced with the calculation result. Otherwise, output Unknown operator! with a newline ('\n') in the end. Then, print Do you want to continue? (y/n) on the next line, with a newline in the end.
• Print the floating-point value directly, without caring about the number of decimal places it should be rounded to.

Example

1 + 2.5
1.000000 + 2.500000 == 3.500000
Do you want to continue? (y/n)
y
1 - 2
1.000000 - 2.000000 == -1.000000
Do you want to continue? (y/n)
y
1 & 2
Unknown operator!
Do you want to continue? (y/n)
n

Explanation: The input is as follows

1 + 2.5
y
1 - 2
y
1 & 2
n

The output is

1.000000 + 2.500000 == 3.500000
Do you want to continue? (y/n)
1.000000 - 2.000000 == -1.000000
Do you want to continue? (y/n)
Unknown operator!
Do you want to continue? (y/n)

Notes

You don't have to print things after input is completely done.

This problem should be solved without arrays or dynamic memory allocation. Keep your solution simple.

Does scanf("%c", ...) skip the leading whitespaces in the input? If you want to read a char in this way, make sure you understand its behavior fully.