 With this assumption, if "X" is a type of operation that may be performed by the data structure, and "n" is an integer defining the size of the given data structure (for instance, the number of items that it contains), then the amortized time for operations of type "X" is defined to be the maximum, among all possible sequences of operations on data structures of size "n" and all operations "oi" of type "X" within the sequence, of the amortized time for operation "oi".With this definition, the time to perform a sequence of operations may be estimated by multiplying the amortized time for each type of operation in the sequence by the number of operations of that type.A dynamic array is a data structure for maintaining an array of items, allowing both random access to positions within the array and the ability to increase the array size by one.