C++: Map vs Vector

What are the main differences between a map and a vector in C++?

In C++, a vector is a dynamic array that allows random access, while a map is an associative container that stores key-value pairs.

When should I use a map instead of a vector?

Use a map when you need to associate keys with values and require fast lookups. Use a vector for ordered collections.

Can you give an example of when a vector would be more efficient?

Sure! If you need to store a list of items and access them by index, a vector is more efficient due to its contiguous memory allocation.

What are the performance implications of using each?

Vectors have O(1) access time, while maps have O(log n) for lookups. Choose based on your access patterns.