What a greedy algorithm is
A greedy algorithm is an approach to solving problems that makes the choice that looks best at each step, without reconsidering previous choices. At every stage, it picks the option that seems most promising right then, hoping that this series of locally optimal choices will lead to a good overall solution. The simplicity of always taking the best immediate option is what defines the greedy approach.
Making the locally best choice
The defining feature of a greedy algorithm is that it decides based on what is best at the current step alone. It does not look far ahead or revisit earlier decisions. Instead, it commits to the choice that appears optimal in the moment and moves on. This makes greedy algorithms straightforward and often fast, because each step involves a simple, immediate decision rather than complex planning.
When greedy works well
For some problems, making the locally best choice at each step really does lead to the best overall answer. In these cases, a greedy algorithm is both simple and correct, producing the optimal solution efficiently. Recognizing which problems have this property is an important part of using greedy algorithms effectively, since the approach is only guaranteed to be correct when the problem's structure supports it.
When greedy falls short
For many problems, always choosing what looks best right now does not lead to the best final result. A choice that seems good early can rule out better options later. In these situations, a greedy algorithm may produce a solution that is only approximate rather than optimal. Understanding this limitation is key: greedy methods are not universally correct and must be applied where they are known to work.
Greedy versus other approaches
Greedy algorithms contrast with approaches that consider more possibilities before deciding, such as dynamic programming, which reuses solutions to subproblems to find optimal answers. Greedy methods are often simpler and faster but can miss the best solution, while more thorough approaches may be slower but more reliably optimal. Choosing between them depends on the problem and whether a greedy choice is known to be safe.
Why it matters
Greedy algorithms are a fundamental problem-solving strategy that is simple and often efficient. Understanding what a greedy algorithm is - making the locally best choice at each step - clarifies both its appeal and its limits. For anyone learning about algorithms, knowing when a greedy approach works, and when it does not, is a valuable skill.
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See also: What is dynamic programming? Explained, What is an algorithm? Explained simply.
Sources
Published date reflects the original event date (2023-06-13). This article is original Skillo editorial written from the sources above; facts were verified in September 2026.
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