85 lines
2 KiB
Markdown
85 lines
2 KiB
Markdown
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# Leetcode Valid-Anagram
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#### 2022-06-14 13:36
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---
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##### Algorithms:
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#algorithm #hash_table
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##### Data structures:
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#DS #array
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##### Difficulty:
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#leetcode #coding_problem #difficulty-easy
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##### Related topics:
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```expander
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tag:#array tag:#hash_table
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```
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- [[Leetcode First-Unique-Character-In-a-String]]
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- [[Leetcode Ransom-Note]]
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##### Links:
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- [Link to problem](https://leetcode.com/problems/valid-anagram/)
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___
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### Problem
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Given two strings `s` and `t`, return `true` _if_ `t` _is an anagram of_ `s`_, and_ `false` _otherwise_.
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An **Anagram** is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once.
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**Follow up:** What if the inputs contain Unicode characters? How would you adapt your solution to such a case?
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#### Examples
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**Example 1:**
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```markdown
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**Input:** s = "anagram", t = "nagaram"
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**Output:** true
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```
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**Example 2:**
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```markdown
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**Input:** s = "rat", t = "car"
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**Output:** false
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```
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#### Constraints
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- `1 <= s.length, t.length <= 5 * 104`
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- `s` and `t` consist of lowercase English letters.
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### Thoughts
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The difference between this and [[Leetcode Ransom-Note]] is that ransom note checks the hash table one way, and this one is bidirectional, which means not only hash map has to be >= 0, it also has to be <= 0, which results in it can only be 0.
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> [!tip]- To understand that
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> Compare this solution with [[Leetcode Ransom-Note#Solution]]
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> to better understand what I mean.
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**Follow up question:**
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Refer to this [site](https://www.cprogramming.com/tutorial/unicode.html) and this [answer](https://stackoverflow.com/questions/3010739/how-to-use-unicode-in-c/3019339#3019339)
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### Solution
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```cpp
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class Solution {
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public:
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bool isAnagram(string s, string t) {
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int hashTable[26] = {};
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for (char c : s) {
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hashTable[c - 'a']++;
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}
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for (char c : t) {
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hashTable[c - 'a']--;
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}
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for (int i : hashTable) {
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if (i != 0) {
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return false;
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}
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}
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return true;
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}
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};
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```
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