Souvenirs of life

The trio of asymptotic complexity (O, Ω, θ) : 1- The Big Oh “O” f (n)=O(g(n))  reads as f on n is big oh of g of n Eg- 5n+5=O (n) means 5n+5≤6n for all n≥5 O (1) that means a constant O (n): linear O (n 2 ): quadratic O (n 3 ): cubic O (2 n ): exponential 2- Omega “Ω” f (n)= Ω(g(n)) reads as f of n is omega of g of n          Eg- 4n+2= Ω means 4n+2≥4n for n≥1 In the case of Oh g(n) is an upper bound on the value of f(n) for all n, n ≥n o   while statement f(n)= Ω (g(n)) states that g(n) only a lower bound on f(n) 3- Theta "θ" f (n)= θ (g(n)) reads f of n is theta of g of n Here f (n) = θ (g (n))            G (n) is both upper and lower bound on f (n.)