1.6 Class of functions
function | |
---|---|
O(1) | constant |
O(logn) | logarithmic |
O(n) | linear |
n^2 | Quadratic |
n^3 | cubic |
O(2^n) | exponential |
1.7 Compare Class of functions
$$ 1 < log (n) < \sqrt n < n < nlog(n) < n^2 < n^3 ... 2^n < 3^n ... n^n $$
functions express the complexity as n increases
1.8 Asymptotic Notations
$$ O() : big-oh : upper bound $$
$$ \Omega : big-omega : lower bound $$
$$ \Theta : Theta : Average bound $$
1.11 Best, worst, and average case analysis
Example : Linear Search
- best case : searching key element present at first index
- O(1)
- Worst case : searching key at last index
- O(n)
- Average case : (all possible cast time) / number of cases
- O(n)
Example : Binary Search
- best case : searching key element present at first index
- O(1)
- Worst case : searching key at last index
- min = O(log n), max = O(n)
- Average case : (all possible cast time) / number of cases
- O(log n)