# How to Use STL Sort?

By now, the fastest comparison sorting algorithm is $$Ο(N\log N)$$. The sort() function in STL implemented with an optimized quicksort, which is always $$O(N\log N)$$.

Here is an example:

# How to Use “Pair” in STL?

In Python, we have tuple, and in Java, we have Map, but in C++, the language itself doesn’t contain anything equivalent. Nevertheless, we can use STL - the Standard Template Library - to construct the data structure.

Of course, we can construct this by ourself, and it’s not complex, but as we will see, with “pair” we can make it easier and simpler.

This is an example:

# How to Record Time in C++?

To record the time your program costs, you can use the function clock(), that is defined in <ctime>. Here is an example showing how to use this function:

# Binary-Search Tree Template

This is a Binary-Search Tree template written by Leon.

# POJ 2418 Hardwood Species

This problem can be solved by at least 4 methods:

• Quick Sort
• Binary Search Tree
• Trie and Depth First Search
• Map