Give an asymptotic lower bound of the form (f (n)) on the worst-case running time. Briefly describe a problem instance which then forces the algorithm to take at least (f (n)) time and proof it.

Algorithm:

for i = i to n{

for j = i+1 to n {

if i != j then{

for k = 1 to n {

if k != i and k!= j and k == i and j then{

break}}}}}