Selecting the right algorithm in competitive programming is a skill that comes from understanding the problem requirements and constraints. Start by analyzing the input size; if the problem involves large data sets, O(n^2) algorithms may be too slow, and an O(n log n) or O(n) solution is preferable. Recognize the type of problem—sorting, searching, graph traversal, or optimization—and match it with commonly used algorithms in those categories. For example, if a problem involves finding shortest paths, algorithms like Dijkstra’s or Floyd-Warshall may be suitable. Familiarity with a broad range of algorithms, from greedy and divide-and-conquer to dynamic programming, gives competitive programmers the flexibility to choose effective solutions quickly. By practicing problem classification and understanding time complexity, programmers can streamline their decision-making process and improve contest performance.