greedy algorithm

A greedy algorithm is an algorithm which, at each step, makes the choice that is locally optimal, and subsequently does not reconsider past choices. Greedy algorithms are often used to solve combinatorial optimization problems. If an optimization problem only depends on the partial solution of solving it for one subproblem, we can solve this problem by "greedily" considering only the locally optimal subproblem. In this sense, a greedy algorithm is a special case of a dynamic programming algorithm. Uriel Feige notes that: [Greedy algorithms] may be viewed as the ultimate form of dynamic programming, in which only one partial solution is maintained. The problem needs to have much more structure for this approach to work.

In many cases, a greedy algorithm does not produce an exact solution, but can yield solutions that approximate an exact solution in a reasonable amount of time.