136th Commit

README.md

@@ -59,9 +59,15 @@ Ace Coding Interview with 75 Qs
 <details>
   <summary>Problems</summary>
 
-| Array / String                  |                                                                                       |      |
-| ------------------------------- | ------------------------------------------------------------------------------------- | ---- |
-| 1768. Merge Strings Alternately | [Solution](./src/page-17/1768.%20Merge%20Strings%20Alternately/merge-alternately.ts) | Easy |
+| Array / String                           |                  |      |
+| ---------------------------------------- | ---------------- | ---- |
+| 1768. Merge Strings Alternately          | [Solution][1768] | Easy |
+| 1071. Greatest Common Divisor of Strings | [Solution][1071] | Easy |
+
+<!-- Array / String -->
+
+[1768]: ./src/page-17/1768.%20Merge%20Strings%20Alternately/merge-alternately.ts
+[1071]: ./src/page-11/1071.%20Greatest%20Common%20Divisor%20of%20Strings/gcdOfStrings.ts
 
 </details>
 
@@ -77,8 +83,12 @@ Must-do List for Interview Prep
 <details>
   <summary>Problems</summary>
 
-| Array / String         |                                                                 |      |
-| ---------------------- | --------------------------------------------------------------- | ---- |
-| 88. Merge Sorted Array | [Solution](./src/page-1//88.%20Merge%20Sorted%20Array/merge.ts) | Easy |
+| Array / String         |                |      |
+| ---------------------- | -------------- | ---- |
+| 88. Merge Sorted Array | [Solution][88] | Easy |
+
+<!-- Array / String -->
+
+[88]: ./src/page-1//88.%20Merge%20Sorted%20Array/merge.ts
 
 </details>

src/page-11/1071. Greatest Common Divisor of Strings/gcdOfStrings.spec.ts

@@ -0,0 +1,9 @@
+import { gcdOfStrings } from './gcdOfStrings';
+
+describe('1071. Greatest Common Divisor of Strings', () => {
+  it('gcdOfStrings', () => {
+    expect(gcdOfStrings('ABCABC', 'ABC')).toBe('ABC');
+    expect(gcdOfStrings('ABABAB', 'ABAB')).toBe('AB');
+    expect(gcdOfStrings('LEET', 'CODE')).toBe('');
+  });
+});

src/page-11/1071. Greatest Common Divisor of Strings/gcdOfStrings.ts

@@ -0,0 +1,29 @@
+type GcdOfStrings = (str1: string, str2: string) => string;
+
+export const gcdOfStrings: GcdOfStrings = (str1, str2) => {
+  // Function to find GCD of two numbers
+  function gcd(a: number, b: number): number {
+    if (b === 0) return a;
+    return gcd(b, a % b);
+  }
+
+  // Function to check if str can divide baseStr
+  function divides(baseStr: string, str: string): boolean {
+    if (baseStr.length % str.length !== 0) return false;
+    const repeatedStr = str.repeat(baseStr.length / str.length);
+    return repeatedStr === baseStr;
+  }
+
+  // Get the GCD of the lengths of the two strings
+  const lenGCD = gcd(str1.length, str2.length);
+
+  // Get the candidate GCD string
+  const candidate = str1.substring(0, lenGCD);
+
+  // Check if the candidate can divide both strings
+  if (divides(str1, candidate) && divides(str2, candidate)) {
+    return candidate;
+  }
+
+  return '';
+};