nSuppose you want to judge two algorithms, A and B, to
find which was better in terms of
running time. You implement both A and B, run them and discover that A took 2 min and B took 1 min 45
sec.
nDoes this prove that
B is better than A?
nWhat if you
standardized a computer, OS, test data, etc.?
nInstead of measuring time computer scientist would
calculate a number of steps necessary to
complete an algorithm. A step is a simple operation like an assignment, comparison, a simple arithmetic
operation, etc.
nEx. Problem:
Calculate the sum of all the integers from 1 to n.
nAlg.#1:
int sum=0; for (int count=1; count<=n; count++) sum += count;
nAlg.
#2 int sum=((n+1)*n)/2;
n