Computers/Algorithm

ch1. definition

emzei 2011. 10. 27. 20:22

algorithm : applying a technique to a problem results in a step-by-step procedure for solving the problem.

 

problem : a question to which we seek answer

 

parameters : variables that are not assigned specific values in the statement of the problem.

 

instance : each specific assignment of values to the parameters.


solution : the answer to the question asked by the problem in that instance.


key : often each item uniquely identifies a record


input size : reasonable measure of the size of the input


time complexity : the determination of how many times the basic operation is done for each value of the input size


T(n) : defined as the number of times the algorithm does the basic operation for an instance of size n // every-case time complexity


W(n) : defined as the maximum number of times the algorithm will ever do its basic operation for an input size of n. worst time complexity


A(n) : defined as the average(expected value) of the number of times the algorithm does the basic operation for an input size of n.


B(n) : defined as the minimum number of times the algorithm will ever do its basic operation for an input size of n.


memory complexity : an analysis of how efficient the algorithm is in terms of memory


complexity function : can be any function that maps the positive integers to the nonnegative reals.


linear time algorithm : algorithms with time complexities such as n and 100n


quadratic time algorithm : algorithalgorithm : applying a technique to a problem results in a step-by-step procedure for solving the problem.

 

problem : a question to which we seek answer

 

parameters : variables that are not assigned specific values in the statement of the problem.

 

instance : each specific assignment of values to the parameters.


solution : the answer to the question asked by the problem in that instance.


key : often each item uniquely identifies a record


input size : reasonable measure of the size of the input


time complexity : the determination of how many times the basic operation is done 

for each value of the input size


T(n) : defined as the number of times the algorithm does the basic operation for an 

instance of size n // every-case time complexity


W(n) : defined as the maximum number of times the algorithm will ever do its basic operation for an input size of n. worst time complexity


A(n) : defined as the average(expected value) of the number of times the algorithm does the basic operation for an input size of n.


B(n) : defined as the minimum number of times the algorithm will ever do its basic operation for an input size of n.


memory complexity : an analysis of how efficient the algorithm is in terms of memory


complexity function : can be any function that maps the positive integers to the nonnegative reals.


linear time algorithm : algorithms with time complexities such as n and 100n


quadratic time algorithm : algorithms with time complexities such as n^2


pure quadratic : contains no linear terms


complete quadratic :  contains linear terms


complexity categories : this means that (order) separates complexity functions into disjoint sets. we’ll call these sets complexity categories. //set of pure complexity functions that order(n), order(n^2), order(n^3)…


big O : asymptotic upper bound


omega : asymptotic lower bound


order : asymptotic tight bound


small o :…

 

divide-and-conquer approach : same strategy on an instance of a problem. top-down approach


tail-recursion : no operations are done after the recursive call


two-way merging : combining two sorted arrays into one sorted array


in-place sort : sorting algorithm that does not use any extra space beyond that needed to store the input.


we use Strassen’s method up to a threshold value of m and use the standard algorithm after reaching the threshold.

 ms with time complexities such as n^2


pure quadratic : contains no linear terms


complete quadratic :  contains linear terms


complexity categories : 


big O : asymptotic upper bound


omega : asymptotic lower bound


order : asymptotic tight bound


small o :…

 

divide-and-conquer approach : same strategy on an instance of a problem. top-down approach


tail-recursion : no operations are done after the recursive call


two-way merging : combining two sorted arrays into one sorted array


in-place sort : sorting algorithm that does not use any extra space beyond that needed to store the input.


we use Strassen’s method up to a threshold value of m and use the standard algorithm after reaching the threshold.

'Computers > Algorithm' 카테고리의 다른 글

은행가 알고리즘  (0) 2016.03.30
몬테카를로 시뮬레이션  (0) 2016.03.30
ch 3. 동적 프로그래밍 (dynamic programming)  (0) 2016.03.25
ch 3. 분할 정복법 (divide-and-conquer)  (0) 2016.03.24
ch 2. efficiency and analysis  (0) 2016.03.24