The conversation between human and AI assistant.
What are the problems on spoj, topcoder and codechef that can easily be solved using C++ STL?
Yes, please explain.
For FCTRL2 on SPOJ, the goal is to calculate factorials of large numbers. Normally, C++ doesn't have a data type that can handle such large numbers. But with C++ STL's BigInteger Library, we can create a data type that allows for arithmetic operations with large numbers.

For SRM 144 DIV 1 - 250 on Topcoder, the problem involves sorting a list of cards and finding the highest score possible. Using C++ STL's set data structure makes it easy to keep track of the cards that have already been played and the possible values that can be achieved.

Finally, for FCTRL on Codechef, we need to calculate the number of trailing zeros in the factorial of a given number. By using C++ STL's map data structure, we can count the number of times each factor appears in the prime factorization of a given number and use that to calculate the number of trailing zeros.