f(n) = n*f(n-1) + f(n-2)

Can this be solved using matrix exponentiation ?

Given an array of integers and a value, how do I efficiently ( better than O(n) ) find the element of the array that gives the maximum result after XORing with the given value?

Can someone help me to find the implementation of Fleury’s Algorithm in c++ or some resources ? thanks in advance :)

Is it possible to find the sum of digit in a ^ b without using Big Int? Where 0 <= a <= 9 & 1<= b <= 4000

How can i solve this ? :(

How many ways to make a number n, using k number of coins from an array of coins?

where 1 <= n <= 10 ^ 9 and 1 <= k <= 10

for example if the array is A[1, 2, 3, 5, 8, 13] and k = 4 and n = 13 . Answer will be 4

as, 1 + 1 + 3 + 8 = 13, 1 + 2 + 2 + 8 = 13, 1 + 2 + 5 + 5 = 13, 2 + 3 + 3 + 5 = 13

Thanks in advance :)