obsidian/АиСД/Задачи/LeetCode/Jewels and Stones.md

Leetcode #771 | #Easy | Хэш-таблицы

Идея

Просто set

Big-O

• Время O(N+M)
• Память O(N)

Код

class Solution {
    public int numJewelsInStones(String jewels, String stones) {
        Set<Character> set = new HashSet<>();
        for (char c : jewels.toCharArray()) set.add(c);
        int res = 0;
        for (char c : stones.toCharArray()) if (set.contains(c)) res++;
        return res;
    }
}