Lecture1
.pdf
Introduction to Algorithms Lecture 1
By: Andrey Bogdanchikov
Gradation Policy
•Every week on Saturday at 15:00 will be Contest.
•Best 7 contests are counted.
•In the end of lecture assignments are given, checked on practice sessions.
Attendance |
– 10% |
Assignments |
– 24% |
Contests and Quizzes – 25% |
|
Midterm exam |
– 16% |
Final exam |
– 25% |
Outline
•Loops
•Find divisors of N
•Perfect number
•Odd number of divisors
•Palindrome
•Sum of digits
•Numeral system
•Zero sequence
Loops
Loops Vocabulary
•Iteration
•Continuation condition
•Statement
•continue statement
•break statement
Find divisors of N
Find divisors of N
1. For i = 1 to N do
2. |
if N mod i = 0 then |
3. |
output i |
Perfect number
Perfect number – where sum of divisors is equal to number itself
1. For N = 1 to M div 2 do 2. sum = 0
3. For i = 1 to N div 2 do 4. if N mod i = 0 then 5. sum = sum + I 6. if sum = N then
7. output N + ” is perfect number”
Odd number of divisors
•How many numbers between 1 and 10000 have odd number of divisors.