How do backtracking and greedy algorithms differ?

How do backtracking and greedy algorithms differ?

Backtracking algorithms explore all possible solutions and backtrack when a solution fails, while greedy algorithms make the best choice at each step without reconsidering previous choices.

Can you give an example of each?

Sure! A classic example of backtracking is the N-Queens problem, where you place queens on a chessboard. A greedy algorithm example is the coin change problem, where you take the largest denomination first.

Which one is more efficient?

It depends on the problem. Greedy algorithms are generally faster but may not always yield the optimal solution, while backtracking can find the optimal solution but may take longer.

When should I use backtracking over greedy?

Use backtracking when you need to explore all possibilities for an optimal solution, especially in combinatorial problems. Use greedy when a local optimum leads to a global optimum.