Problem - D - Codeforces It is easy to realize that once the first two elements are determined, the rest in the Fibonacci sequence are determined as well. Another important property is that Fibonacci sequence expands exponentially, and giv…

Problem - C - Codeforces Reverse the text, and perform dynamic programming to mark if some index i is possible to be reached from some index j, and the word it should use to reach from j to i. Make use of Rabin-Karp hashing to accelerate w…