*

content/series/algorithms-problem-solving/cracking-the-coding-interview-check-permutation/en/index.mdx

@@ -0,0 +1,83 @@
+<SmoothRender>
+
+This post is part of the [`Algorithms Problem Solving`](/series/algorithms-problem-solving) series and a problem from the Cracking the Coding Interview book.
+
+## Problem description
+
+Given two strings, write a method to decide if one is a permutation of the other
+
+## Examples
+
+```JavaScript
+// input: 'aba', 'aab'
+// output: true
+
+// input: 'aba', 'aaba'
+// output: false
+
+// input: 'aba', 'aa'
+// output: false
+```
+
+## Solutions
+
+If they have different lengths, they are not permutations.
+
+Build a hashmap of characters of one of the strings
+Iterate through the other string and check if the characters are in the hashmap
+If there's no match in the hashmap, they are not permutations
+If it passes the loop, they are permutations.
+
+- Runtime Complexity: O(N), where N = the length of the string
+- Space Complexity: O(N), where N = the length of the string
+
+```JavaScript
+function buildCharsMap(string) {
+  const charsMap = new Map();
+
+  for (let char of string) {
+    if (charsMap.has(char)) charsMap.set(char, charsMap.get(char) + 1);
+    else charsMap.set(char, 1);
+  }
+
+  return charsMap;
+}
+
+function checkPermutation(s1, s2) {
+  if (s1.length !== s2.length) return false;
+  const charsMap = buildCharsMap(s1);
+
+  for (let char of s2) {
+    if (!charsMap.has(char)) {
+      return false;
+    }
+
+    if (charsMap.get(char) === 0) {
+      return false;
+    }
+
+    charsMap.set(char, charsMap.get(char) - 1);
+  }
+
+  return true;
+}
+```
+
+## Resources
+
+- [Algorithms Problem Solving Series](/series/algorithms-problem-solving)
+- [Algorithms & Data Structures studies](https://github.com/imteekay/algorithms)
+- [Is Unique source code](https://github.com/imteekay/algorithms/blob/master/coding_interviews/cracking-the-coding-interview/string/is-unique/is-unique.js)
+- [Data Structures in JavaScript Series](/series/data-structures-in-javascript)
+- [Stack Data Structure in JavaScript](/series/data-structures-in-javascript/stack-data-structure)
+- [Queue Data Structure in JavaScript](/series/data-structures-in-javascript/queue-data-structure)
+- [Linked List Data Structure in JavaScript](/series/data-structures-in-javascript/linked-list-data-structure)
+- [Tree Data Structure in JavaScript](/series/data-structures-in-javascript/tree-data-structure)
+- [Stack Data Structure](/series/data-structures/stack-data-structure)
+- [Queue Data Structure](/series/data-structures/queue-data-structure)
+- [Linked List](/series/data-structures/linked-list-data-structure)
+- [Tree Data Structure](/series/data-structures/tree-data-structure)
+
+---
+
+</SmoothRender>

content/series/algorithms-problem-solving/cracking-the-coding-interview-check-permutation/en/metadata.json

@@ -0,0 +1,23 @@
+{
+  "title": "Cracking the Coding Interview: Check Permutation",
+  "description": "Solving algorithmic problems, algorithmic techniques, and cracking the coding interview",
+  "date": "2023-09-25",
+  "tags": [
+    {
+      "href": "/tags/javascript",
+      "name": "javascript"
+    },
+    {
+      "href": "/tags/algorithms-and-data-structures",
+      "name": "algorithms_and_data_structures"
+    }
+  ],
+  "coverImage": {
+    "src": "/series/algorithms-problem-solving/check-permutation.jpg",
+    "width": "640",
+    "height": "426",
+    "alt": "3x3 Rubik's Cube",
+    "authorHref": "https://unsplash.com/@jlxp",
+    "authorName": "Jean-Louis Paulin"
+  }
+}

content/series/algorithms-problem-solving/en/index.mdx

@@ -171,6 +171,11 @@ This is live document and will be updated everytime I solve new problems.
     title="Cracking the Coding Interview: Is Unique"
     url="/series/algorithms-problem-solving/cracking-the-coding-interview-is-unique"
   />
+  <PostAndDate
+    date="2023-09-25"
+    title="Cracking the Coding Interview: Check Permutation"
+    url="/series/algorithms-problem-solving/cracking-the-coding-interview-check-permutation"
+  />
 </ul>
 
 ---

content/tags/algorithms-and-data-structures/en/index.mdx

@@ -3,6 +3,11 @@
 ## 2023
 
 <ul>
+  <PostAndDate
+    date="2023-09-25"
+    title="Cracking the Coding Interview: Check Permutation"
+    url="/series/algorithms-problem-solving/cracking-the-coding-interview-check-permutation"
+  />
   <PostAndDate
     date="2023-09-24"
     title="Cracking the Coding Interview: Is Unique"