# CSPT13 Lecture 14
## [Jewels and Stones](https://leetcode.com/problems/jewels-and-stones)

class Solution:
    """
    Understand
    
    jewels = "aA", stones = "aAAbbbb"
    output: 3
    
    jewels = "" stones = "ab"
    output: 0
    
    jewels = "a" stones = "aaa"
    output: 3
    
    Plan
    jewels = "aA", stones = "aAAbbbb"
    
    j = {a, A}
    
    1. make a set out of jewels
    2. go through stones and count how many stones are jewels
    
    Runtime: O(S + J)
    Space: O(J)
    """
    def numJewelsInStones(self, jewels: str, stones: str) -> int:
        j = set(jewels)
        numJewels = 0
        for stone in stones:
            if stone in j:
                numJewels += 1
        return numJewels

## [Uncommon Words](https://leetcode.com/problems/uncommon-words-from-two-sentences)

from collections import defaultdict
class Solution:
    """
    Input: A = "this apple is sweet", B = "this apple is sour"
    Output: ["sweet","sour"]
    
    A = "apple apple" B = "banana"
    Output: ["banana"]
    
    A = "apple orange" B = "rambutan mango"
    Output: ["apple", "orange", "rambutan", "mango"]
    
    A = "apple apple" B = "mango mango"
    Output = []
    
    Plan
    A = "apple apple" B = "banana"
    
    c = {apple: 2, banana: 1}
    res = ["banana"]
    
    Create one dictionary that contain the word count of both sentences
    Go through each word in both sentences
        If a word has count of 1 then that means 
        it only occurs in one sentence
            add that to our result
    return result
    
    A = "apple apple" B = "banana"
    wordCount = {apple: 2, banana: 1}
    C = "apple apple banana"
    listC = [apple, apple, banana]
    res = [banana]
    
    Runtime: O(A + B)
    Space: O(A + B)
    """
    def uncommonFromSentences(self, A: str, B: str) -> List[str]:
        wordCount = defaultdict(int)
        C = A + " " + B
        listC = C.split(" ")
        
        for word in listC:
            wordCount[word] += 1
        
        res = []
        for word in listC:
            if wordCount[word] == 1:
                res.append(word)
        
        return res