/breakfast-calculator

Primary LanguageJavaScript

Goal: determine quantities of breakfast ingredients to meet dietary requirements

Constraints:

  • For simplicity, let's assume everything can be divided by gram (as opposed to, e.g., eggs)
  • Let's only consider breakfasts composed of combined raw ingredients where all ingredients can be of arbitrary quantities (i.e. not proportional to one another)
  • Output ingredients must meet dietary requirements, or within threshold

Input:

  • available ingredients
    • type
    • maximum quantity
  • nutritional content goals
  • acceptable margin of error (e.g. 2% above or below dietary goal is acceptable)

Output:

  • ingredients
    • type
    • desired quantity
    • nutritional content
  • total nutritional content

Notes:

  • This is a constraint satisfaction problem, possibly more suited to a language like Prolog.
  • Options detailed below, but in both cases I have to get the data from somewhere and then hook it all up. Probably it'd be better to use an existing solution.

Implementation options:

  1. Constraint satisfaction by hand - If no unused ingredients remain
    • fail - Choose one ingredient from the list of remaining ingredients: A) Construct a choicepoint including:
      • The included ingredients so far
      • Remaining ingredients
      • Previously attempted choices ([ingredient])
    • Include the maximum of that ingredient without exceeding dietary requirements
    • If the dietary requirements are satisfied, return
    • Else if some ingredients remain, recurse
    • Else, backtrack:
      • Take the most recent choicepoint
        • If it has possible choices remaining, repeat from A) with a different choice
        • Else, pop it from the stack and try the next choicepoint
  2. Use a prebuilt constraint-satisfaction library - Figure out how to use it - Get nutrition data - Hook it all up

Choicepoint stack: [] Current state: ingredients used, goals

  • ([], [A, B, C])
    • Choose A
    • ([A], [B, C])
      • Choose B
      • ([A,B], [C])
        • Backtrack!
      • ([A], [B, C])
        • Choose C
        • ([A, C], [B])
          • Choose B
          • ([A, C, B], [])
            • Satisfied? Success.
            • Unsatisfied? Backtrack.