1D/2D Arrays

Arrays are collections of elements of the same type stored in contiguous memory locations. A 1D array is the simplest form, a linear sequence of elements accessed by a single index. Understanding that `arr[i]` is essentially syntactic sugar for `*(arr + i)` is crucial for grasping how pointers and arrays relate in languages like C++. A 2D array, or matrix, can be thought of as an array of arrays. In memory, it is typically stored in row-major order, where all elements of the first row are stored contiguously, followed by all elements of the second row, and so on. This layout has implications for performance, particularly cache efficiency. Traversing a 2D array row by row is generally faster than traversing column by column because it accesses memory sequentially, which is cache-friendly. Common traversal patterns for 2D arrays, beyond the standard nested loops, include spiral traversal, diagonal traversal, and rotating the matrix. These problems test your ability to manipulate indices carefully and manage boundary conditions. A solid command of basic array operations and memory layout is the foundation upon which more advanced techniques are built. It's essential to be comfortable with initializing, accessing, and iterating over both 1D and 2D arrays before moving on to more complex algorithms.