answer question

jenny2000000

I399_Lecture_5.pptx

Home >Reading homework help >answer question

I399 – Problem solving Techniques

Lecture 7

Today

Midterm

P a r t 1:

W h y

Why we do this

Critical thinking!

Problem solving!

Keys to Mastery

Repetition

Challenge

Define the Problem

don't jump into trying to solve

read

re read

remain open minded

clarify

break it down

refine/be specific

figure out whys of the problem

P a r t 2:

Q u e s t i o n 1

1. You have 20 coins in a row. Ten are heads up, ten are tails up. The order is random. You also have a robot that can perform 4 different actions:

Move itself one coin's width to the left or right at a time.

See the heads/tails status of the two coins directly in front of it.

Flip over both of the two coins that it sees.

Remember a number

Can you give the robot a set of instructions that will result in all 20 coins eventually being turned heads up using only the capabilities outlined above? If not, why? If so, what are the instructions?

Understand

Look for relations

Activity revisited

Can we flip successive pairs to leave only heads facing up?

Activity revisited

Either increase heads by 2

Decrease heads by 2

Or number remains unchanged

Simplify

Activity revisited

look at 2 coins in front

if left is a tails, flip both

move one step to the right

repeat from 2

Activity revisited

remember the number 1

look at the 2 coins the robot can see

if left is a tails, flip both

move one step to the right

increase the number remembered by one

if only one coin can be seen in front of robot:

If number matches number of coins, Finish

otherwise: take one step to the left

swap all instances of left and right

change number remembered to 1

repeat from 3

Number: 1

Number: 2

Number: 3

Number: 4

Number: 5

Number: 6

Number: 1

Number: 2

Number: 3

Number: 4

Number: 5

Number: 6

Number: 7

Number: 8

finish

testing a solution

clarifications

edge cases

P a r t 3:

Q u e s t i o n 2

move space one to left

move space one to right

move space two to left

move space two to right

slide left facing coin left

slide right facing coin right

jump left facing coin left

jump right facing coin right

look for patterns

explore pattern

start small

keep trying

look for patterns

start direction left

move space in direction by sliding

make as many jumps over opposite pieces going direction as possible

switch direction

repeat from step 2 until can no longer move space, then switch to:

switch direction

move space in direction by sliding

make as many jumps over opposite pieces going opposite direction as possible

repeat from step 6

1. start direction left

2. move space in direction by sliding

3. make as many jumps over opposite pieces going direction as possible

4. switch direction

5. repeat from step 2 until can no longer move space

2. move space in direction by sliding

3. make as many jumps over opposite pieces going direction as possible

4. switch direction

5. repeat from step 2 until can no longer move space

2. move space in direction by sliding

3. make as many jumps over opposite pieces going direction as possible

4. switch direction

5. repeat from step 2 until can no longer move space

2. move space in direction by sliding

3. make as many jumps over opposite pieces going direction as possible

4. switch direction

5. repeat from step 2 until can no longer move space

then switch to:

6. switch direction