Which of the following is an example of a divide and conquer recurrence?
T(n)=2T(n/2)+O(n)T(n) = 2T(n/2) + O(n)T(n)=2T(n/2)+O(n)
T(n)=T(n−1)+nT(n) = T(n-1) + nT(n)=T(n−1)+n
an=3an−1+2a_n = 3a_{n-1} + 2an=3an−1+2
an=an−1+an−2a_n = a_{n-1} + a_{n-2}an=an−1+an−2