How to convert user's string input into a number in C++

Question

I'm trying to calculate food price via user input.
Currently struggling to convert user's string inputs into numbers.

Please take a look: https://code.sololearn.com/ciEyabQ2RxhT/#cpp

Lastly, how could I specify that the input should be separated by spaces?

Answer 1

https://code.sololearn.com/cuOtj826z9Cc/?ref=app