The following articles contain lists of problems:
- List of undecidable problems
- Lists of unsolved problems
- List of NP-complete problems
- List of PSPACE-complete problems
This article includes a list of lists.
The following articles contain lists of problems:
In mathematics and computer science, an algorithm is a finite sequence of rigorous instructions, typically used to solve a class of specific problems or to perform a computation. Algorithms are used as specifications for performing calculations and data processing. More advanced algorithms can use conditionals to divert the code execution through various routes and deduce valid inferences, achieving automation eventually. Using human characteristics as descriptors of machines in metaphorical ways was already practiced by Alan Turing with terms such as "memory", "search" and "stimulus".
The P versus NP problem is a major unsolved problem in theoretical computer science. In informal terms, it asks whether every problem whose solution can be quickly verified can also be quickly solved.
In theoretical computer science and mathematics, computational complexity theory focuses on classifying computational problems according to their resource usage, and relating these classes to each other. A computational problem is a task solved by a computer. A computation problem is solvable by mechanical application of mathematical steps, such as an algorithm.
In mathematics, graph theory is the study of graphs, which are mathematical structures used to model pairwise relations between objects. A graph in this context is made up of vertices which are connected by edges. A distinction is made between undirected graphs, where edges link two vertices symmetrically, and directed graphs, where edges link two vertices asymmetrically. Graphs are one of the principal objects of study in discrete mathematics.
In computer science, a linked list is a linear collection of data elements whose order is not given by their physical placement in memory. Instead, each element points to the next. It is a data structure consisting of a collection of nodes which together represent a sequence. In its most basic form, each node contains: data, and a reference to the next node in the sequence. This structure allows for efficient insertion or removal of elements from any position in the sequence during iteration. More complex variants add additional links, allowing more efficient insertion or removal of nodes at arbitrary positions. A drawback of linked lists is that access time is linear. Faster access, such as random access, is not feasible. Arrays have better cache locality compared to linked lists.
Time management is the process of planning and exercising conscious control of time spent on specific activities, especially to increase effectiveness, efficiency, and productivity. It involves of various demands upon a person relating to work, social life, family, hobbies, personal interests, and commitments with the finite nature of time. Using time effectively gives the person "choice" on spending or managing activities at their own time and expediency. Time management may be aided by a range of skills, tools, and techniques used to manage time when accomplishing specific tasks, projects, and goals complying with a due date. Initially, time management referred to just business or work activities, but eventually, the term broadened to include personal activities as well. A time management system is a designed combination of processes, tools, techniques, and methods. Time management is usually a necessity in any project management as it determines the project completion time and scope.
The subset sum problem (SSP) is a decision problem in computer science. In its most general formulation, there is a multiset of integers and a target-sum , and the question is to decide whether any subset of the integers sum to precisely . The problem is known to be NP-hard. Moreover, some restricted variants of it are NP-complete too, for example:
In computational complexity theory, a decision problem is P-complete if it is in P and every problem in P can be reduced to it by an appropriate reduction.
Hilbert's problems are 23 problems in mathematics published by German mathematician David Hilbert in 1900. They were all unsolved at the time, and several proved to be very influential for 20th-century mathematics. Hilbert presented ten of the problems at the Paris conference of the International Congress of Mathematicians, speaking on August 8 at the Sorbonne. The complete list of 23 problems was published later, in English translation in 1902 by Mary Frances Winston Newson in the Bulletin of the American Mathematical Society.
The William Lowell Putnam Mathematical Competition, often abbreviated to Putnam Competition, is an annual mathematics competition for undergraduate college students enrolled at institutions of higher learning in the United States and Canada. It awards a scholarship and cash prizes ranging from $250 to $2,500 for the top students and $5,000 to $25,000 for the top schools, plus one of the top five individual scorers is awarded a scholarship of up to $12,000 plus tuition at Harvard University, the top 100 individual scorers have their names mentioned in the American Mathematical Monthly, and the names and addresses of the top 500 contestants are mailed to all participating institutions. It is widely considered to be the most prestigious university-level mathematics competition in the world, and its difficulty is such that the median score is often zero despite being attempted by students specializing in mathematics.
In mathematics, the Gauss class number problem, as usually understood, is to provide for each n ≥ 1 a complete list of imaginary quadratic fields having class number n. It is named after Carl Friedrich Gauss. It can also be stated in terms of discriminants. There are related questions for real quadratic fields and for the behavior as .
A cello sonata is usually a sonata written for solo cello with piano accompaniment. The most famous Romantic-era cello sonatas are those written by Johannes Brahms and Ludwig van Beethoven. Some of the earliest cello sonatas were written in the 18th century by Francesco Geminiani and Antonio Vivaldi.
A checklist is a type of job aid used in repetitive tasks to reduce failure by compensating for potential limits of human memory and attention. It helps to ensure consistency and completeness in carrying out a task. A basic example is the "to do list". A more advanced checklist would be a schedule, which lays out tasks to be done according to time of day or other factors. A primary task in checklist is documentation of the task and auditing against the documentation.
Automated planning and scheduling, sometimes denoted as simply AI planning, is a branch of artificial intelligence that concerns the realization of strategies or action sequences, typically for execution by intelligent agents, autonomous robots and unmanned vehicles. Unlike classical control and classification problems, the solutions are complex and must be discovered and optimized in multidimensional space. Planning is also related to decision theory.
Overlearning refers to practicing newly acquired skills beyond the point of initial mastery. The term is also often used to refer to the pedagogical theory that this form of practice leads to automaticity or other beneficial consequences.
A report is a document that presents information in an organized format for a specific audience and purpose. Although summaries of reports may be delivered orally, complete reports are almost always in the form of written documents.
List of unsolved problems may refer to several notable conjectures or open problems in various academic fields:
Various lists of the Wonders of the World have been compiled from antiquity to the present day, in order to catalogue the world's most spectacular natural features and human-built structures.
Pedubast II was a pharaoh of Ancient Egypt associated with the 22nd or more likely the 23rd Dynasty. Not mentioned in all King lists, he is mentioned as a possible son and successor to Shoshenq V by Aidan Dodson and Dyan Hilton in their 2004 book The Complete Royal Families of Ancient Egypt. They date his reign at about 743–733 BC, between Shoshenq V and Osorkon IV.
In computational complexity theory, a problem is NP-complete when: