给定一个长字符串，在字典中找到匹配的字符串

Question

Let's assume that we have a dictionary whose keys are the food names.

A user can input a food name string (ie "banana yogurt steak cheese cake"), and for the sake of simplicity, let's assume that everything is lower-case, and no food name appears more than once in the string.

What would be the most efficient way to find out what keys from the dictionary appeared in the food name string? Let's assume that it's possible that no key appears at all, and it's also possible that food name string only consists of the dictionary keys.

This is for self-study purpose. Use of Suffix Trie seems to be a good option, but I'm not sure how to optimize it (since there are possibly multiple matches in this case) If there are well-known theorems or references for it, i would really appreciate it.

PS. Thanks for the answer, but the only problem is that the food name doesn't need to be one word long . Let's think of something like this.

"mild coffee ice cream"

it's 4 word long string, but only 2 food names: mild coffee, ice cream

Answer 1

You can use set intersection for that purpose:

set(food_string.split()) & food_dict.keys()

Note that dict.keys() , although not a set , supports the set API.

If no unambiguous boundary for food names can be identified (such as space), then you can use the following:

[k for k in food_dict if k in food_string]

Answer 2

Is this what you meant?

dict = {
  "banana": "answer1",
  "steak": "answer1",
  "cheese": "answer1"
}
input = "banana yogurt steak cheese cake"
for word in input.split():
    print (word)
    if word in dict:
        print ("true")

Output:

banana
true
yogurt
steak
true
cheese
true
cake

If it's not one word:

dict = {
  "banana milk shake": "answer1",
  "steak": "answer2",
  "ice cream": "answer3",
  "salad dressing": "answer4"
}
input = "banana milk shake yogurt steak cheese ice cream cake"
for key in dict:
    print (key)
    if key in input:
        print ("true")
    else:
        print ("false")

Output:

banana milk shake
true
steak
true
ice cream
true
salad dressing
false