Mathematical Preliminaries The Factorial Function Permutations Logarithms Summations Recurrence Relations Algorithm Analysis

The Factorial Function Definition: Stirling’s approximation:

Permutations A permutation of a sequence is the members of a sequence arranged in some order. There are n! different permutations for a sequence with n distinct members. To generate a permutation of an array: void permute(int *a, int n) { for (int i = n; i > 0; i--) swap(a[i - 1], a[random(i)]); }

Logarithms

Summations

Recurrence Relations For the factorial function: For the Fibonacci sequence:

Algorithm Analysis The time T to run an algorithm as a function of n is written as T(n) T(n) is in the set O(f(n)) if there are two positive constants c and n 0 such that If the upper bound (highest growth rate) for an algorithm is f(n) then it is in O(f(n)) in the worst case For all inputs that are large enough, the algorithm always executes in less time than

Comparison of Running Times in Increasing Order O(1) O(log n) O(n) O(n log n) O(n c ) O(c n )