Integer Integer An integer (from the Latin "integer" meaning "whole") is a number that can be written without a fractional component. For example, 21, 4, 0, and −2048 are integers, while 9.75, , and are not. The set of integers consists of zero (), the positive natural numbers (, , , …), also called "whole numbers" or "counting numbers", and their additive inverses (the negative integers, i.e., −1, −2, −3, …). The set of integers is often denoted by a boldface Z ("") or blackboard bold formula_1 (Unicode U+2124 ℤ) standing for the German word "Zahlen" (, "numbers"). The integers form
Adaptive sort sorted items. In pseudo-code form, the "Straight Insertion Sort" algorithm could look something like this (array X is zero-based): The performance of this algorithm can be described in terms of the number of inversions in the input, and then will be roughly equal to , where is the number of Inversions. Using this measure of presortedness – being relative to the number of inversions – "Straight Insertion Sort" takes less time to sort the closer it is to being sorted. Other examples of adaptive sorting algorithms are adaptive heap sort, adaptive merge sort, patience sort, Shellsort, smoothsort, splaysort and Timsort.