What is the most commonly used data structure?

Answer 1

Vectors (variable-length arrays) are the most commonly used data structure because a vector has the lowest memory overhead of any data container with the exception of fixed-length arrays (the second most-used container). All elements of a vector (and an array) must be of the same type and therefore of the same length, and are allocated in contiguous memory. Each element is identified by a subscript (a zero-based offset index) such that an array of n elements has subscripts in the range 0 to n-1. Subscripting makes it possible to perform bi-directional traversal as well as random-access in constant-time.