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A201 (I201, A597) Introduction to Programming
Adrian German ([email protected])
Office: Lindley Hall (LH) 201D
Class home page containing
ALL
the details:
http://www.cs.indiana.edu/classes/a201
Please check the “What’s New” part of the web page every day!
The purpose of this class:
The purpose of this class:
- to get to know each other better
The purpose of this class:
- to get to know each other better
- to understand programming in Java
The purpose of this class:
- to get to know each other better
- to understand programming in Java
- to improve our problem solving skills
The purpose of this class:
- to get to know each other better
- to understand programming in Java
- to improve our problem solving skills
A reminder:
The purpose of this class:
- to get to know each other better
- to understand programming in Java
- to improve our problem solving skills
A reminder:
Education is what remains after we forget
what we learned in school.
The purpose of this class:
- to get to know each other better
- to understand programming in Java
- to improve our problem solving skills
A reminder:
Education is what remains after we forget
what we learned in school.
But we have to learn it first!
What is Programming?
What is Programming?
What does it look like?
What is Programming?
What does it look like?
Let’s work out some examples.
First Problem
First Problem
You are given two (different length) strings
First Problem
You are given two (different length) strings that
have the characteristic that they both take exactly
one hour to burn.
First Problem
You are given two (different length) strings that
have the characteristic that they both take exactly
one hour to burn. However, neither string burns at a
constant rate.
First Problem
You are given two (different length) strings that
have the characteristic that they both take exactly
one hour to burn. However, neither string burns at a
constant rate. Some sections of the strings burn
very fast; other sections burn very slowly.
First Problem
You are given two (different length) strings that
have the characteristic that they both take exactly
one hour to burn. However, neither string burns at a
constant rate. Some sections of the strings burn
very fast; other sections burn very slowly. All you
have to work with is a box of matches and the two
strings.
First Problem
You are given two (different length) strings that
have the characteristic that they both take exactly
one hour to burn. However, neither string burns at a
constant rate. Some sections of the strings burn
very fast; other sections burn very slowly. All you
have to work with is a box of matches and the two
strings. Describe an algorithm that uses the strings
and the matches to calculate when exactly 45
minutes have elapsed.
Second Problem
Second Problem
A farmer lent the mechanic next door a 40-pound
weight.
Second Problem
A farmer lent the mechanic next door a 40-pound
weight. Unfortunately, the mechanic dropped the
weight and it broke into four pieces.
Second Problem
A farmer lent the mechanic next door a 40-pound
weight. Unfortunately, the mechanic dropped the
weight and it broke into four pieces. The good news
is that, according to the mechanic, it is still
possible to use the four pieces to weigh any
quantity between one and 40 pounds on a balance
scale.
Second Problem
A farmer lent the mechanic next door a 40-pound
weight. Unfortunately, the mechanic dropped the
weight and it broke into four pieces. The good news
is that, according to the mechanic, it is still
possible to use the four pieces to weigh any
quantity between one and 40 pounds on a balance
scale.
Note: you can weigh a 4-pound object on a balance by
putting a 5-pound weight on one side and a 1-pound
weight on the other.
Third Problem
Third Problem
A captive queen weighing 195 pounds,
Third Problem
A captive queen weighing 195 pounds, her son
weighing 90 pounds,
Third Problem
A captive queen weighing 195 pounds, her son
weighing 90 pounds, and her daughter weighing
165 pounds
Third Problem
A captive queen weighing 195 pounds, her son
weighing 90 pounds, and her daughter weighing
165 pounds, were trapped in a very high tower.
Third Problem
A captive queen weighing 195 pounds, her son
weighing 90 pounds, and her daughter weighing
165 pounds, were trapped in a very high tower.
Outside their window was a pulley and rope
with a basket fastened on each end.
Third Problem
A captive queen weighing 195 pounds, her son
weighing 90 pounds, and her daughter weighing
165 pounds, were trapped in a very high tower.
Outside their window was a pulley and rope
with a basket fastened on each end. They
managed to escape
Third Problem
A captive queen weighing 195 pounds, her son
weighing 90 pounds, and her daughter weighing
165 pounds, were trapped in a very high tower.
Outside their window was a pulley and rope
with a basket fastened on each end. They
managed to escape by using the baskets and a
75-pound weight they found in the tower.
Third Problem
A captive queen weighing 195 pounds, her son
weighing 90 pounds, and her daughter weighing
165 pounds, were trapped in a very high tower.
Outside their window was a pulley and rope
with a basket fastened on each end. They
managed to escape by using the baskets and a
75-pound weight they found in the tower. How
did they do it?
Third Problem
A captive queen weighing 195 pounds, her son
weighing 90 pounds, and her daughter weighing
165 pounds, were trapped in a very high tower.
Outside their window was a pulley and rope
with a basket fastened on each end. They
managed to escape by using the baskets and a
75-pound weight they found in the tower. How
did they do it?
The problem is that anytime the difference in
weight between the two baskets is more than 15
pounds, someone might get killed.
Third Problem
A captive queen weighing 195 pounds, her son
weighing 90 pounds, and her daughter weighing
165 pounds, were trapped in a very high tower.
Outside their window was a pulley and rope
with a basket fastened on each end. They
managed to escape by using the baskets and a
75-pound weight they found in the tower. How
did they do it?
The problem is that anytime the difference in
weight between the two baskets is more than 15
pounds, someone might get killed. Describe an
algorithm that gets them down safely.
A Story
Shakey the Robot()
Based on a character created by Suzanne Menzel
The place is here (RH100) the time is in the future.
You are about to enter the sixth dimension… Hang in there! Hang in there!
red lines are solid walls (nothing can go through)
(0,0)
(0,0)
(0,1)
(0,0)
(0,1)
(0,2)
(0,0)
(0,1)
(0,2)
(1,0)
(1,1)
(1,2)
(2,0)
(2,1)
(2,2)
Robot shakey;
(0,0)
(0,1)
(0,2)
(1,0)
(1,1)
(1,2)
(2,0)
(2,1)
(2,2)
Robot shakey;
shakey = new Robot();
shakey
new Robot();
(0,0)
(0,1)
(0,2)
(1,0)
(1,1)
(1,2)
(2,0)
(2,1)
(2,2)
Robot shakey;
shakey = new Robot();
shakey.placeAt(2, 1, “North”);
shakey
(0,0)
(0,1)
(0,2)
(1,0)
(1,1)
(1,2)
(2,0)
(2,1)
(2,2)
Robot shakey;
shakey = new Robot();
shakey.placeAt(2, 1, “North”);
(0,0)
(0,1)
(0,2)
(1,0)
(1,1)
(1,2)
(2,0)
(2,1)
(2,2)
a Robot (only) knows how to:
turn
left()
move forward()
Robot shakey;
shakey = new Robot();
shakey.placeAt(2, 1, “North”);
shakey.left();
(0,0)
(0,1)
(0,2)
(1,0)
(1,1)
(1,2)
(2,0)
(2,1)
(2,2)
Robot shakey;
shakey = new Robot();
shakey.placeAt(2, 1, “North”);
shakey.left();
shakey.forward();
(0,0)
(0,1)
(0,2)
(1,0)
(1,1)
(1,2)
(2,0)
(2,1)
(2,2)
Robot shakey;
shakey = new Robot();
shakey.placeAt(2, 1, “North”);
shakey.left();
shakey.forward();
(0,0)
(0,1)
(0,2)
(1,0)
(1,1)
(1,2)
(2,0)
(2,1)
(2,2)
a Robot (only) knows how to:
turn
left()
move forward()
Robot shakey;
shakey = new Robot();
shakey.placeAt(2, 1, “North”);
shakey.left();
shakey.forward();
shakey.left();
(0,0)
(0,1)
(0,2)
(1,0)
(1,1)
(1,2)
(2,0)
(2,1)
(2,2)
Robot shakey;
shakey = new Robot();
shakey.placeAt(2, 1, “North”);
shakey.left();
shakey.forward();
shakey.left();
(0,0)
shakey.left();
(0,1)
(0,2)
(1,0)
(1,1)
(1,2)
(2,0)
(2,1)
(2,2)
Robot shakey;
shakey = new Robot();
shakey.placeAt(2, 1, “North”);
shakey.left();
shakey.forward();
shakey.left();
(0,0)
shakey.left();
shakey.left();
(0,1)
(0,2)
(1,0)
(1,1)
(1,2)
(2,0)
(2,1)
(2,2)
Robot shakey;
shakey = new Robot();
shakey.placeAt(2, 1, “North”);
shakey.left();
shakey.forward();
shakey.left();
(0,0)
shakey.left();
shakey.left();
shakey.forward();
(0,1)
(0,2)
(1,0)
(1,1)
(1,2)
(2,0)
(2,1)
(2,2)
Robot shakey;
shakey = new Robot();
shakey.placeAt(2, 1, “North”);
shakey.left();
shakey.forward();
shakey.left();
(0,0)
shakey.left();
shakey.left();
shakey.forward();
shakey.forward();
(0,1)
(0,2)
(1,0)
(1,1)
(1,2)
(2,0)
(2,1)
(2,2)
Well done, Shakey, way to go!