Swift for Coding Interviews

The Swift you need for algorithm rounds: strings, collections, data structures, patterns and ready-to-use templates.

1. 01
   Strings

   How Swift strings work, how to index them fast, the everyday operations, and the performance traps that turn O(n) into O(n²).

   3 min
2. 02
   Collections

   Array, Dictionary, Set and tuples in Swift, sorting with closures, reduce, zip, enumerated, 2D arrays, and the Big-O of each operation.

   2 min
3. 03
   Building Blocks

   Swift has no built-in stack, queue, deque or heap. Here is how to write each one quickly, plus linked lists, tree nodes and graph adjacency lists.

   3 min
4. 04
   Patterns

   When to use two pointers, sliding window, hashing, binary search and prefix sums, with a short Swift template for each.

   3 min
5. 05
   Trees and Graphs

   DFS and BFS on trees, graphs and grids (recursive and iterative), topological sort and union-find, as Swift templates.

   3 min
6. 06
   Recursion and Dynamic Programming

   Recursion and backtracking in Swift, memoization with dictionaries and arrays, bottom-up tables, and the common DP shapes with templates.

   4 min