introduction to problem solvings1.2.1 bina © 1998 liran & ofir introduction to problem solving...

Introduction to Problem Solving S1.2.1Bina © 1998 Liran & Ofir

Introduction to Problem SolvingIntroduction to Problem SolvingIntroduction to Problem SolvingIntroduction to Problem Solving

Programming in Programming in

CC


Problem SolvingProblem SolvingProblem SolvingProblem Solving

Describe the steps that the computerDescribe the steps that the computer should take in order to solve the problemshould take in order to solve the problem

How to get the computer solve a problem?How to get the computer solve a problem?

AlgorithmAlgorithm


Steps of Problem SolvingSteps of Problem SolvingSteps of Problem SolvingSteps of Problem Solving

11. Understand the problem to be solved. Understand the problem to be solved

AnalysisAnalysis

22. Devise a solution to the problem . Devise a solution to the problem

Algorithm DesignAlgorithm Design



33. Verify that the solution is correct. Verify that the solution is correct

Desk checkDesk check

44. Describe the solution using a programming. Describe the solution using a programming languagelanguage

ProgrammingProgramming



55. Verify that the program does state the. Verify that the program does state the solution correctlysolution correctly

TestingTesting


Understand the problemUnderstand the problemUnderstand the problemUnderstand the problem

What is the problem?What is the problem?

What are the inputs?What are the inputs?

What are the outputs?What are the outputs?

What are examples of input output What are examples of input output

relationships?relationships?




Compute the average of 3 numbersCompute the average of 3 numbers




Input: 3 valuesInput: 3 values



What are the outputsWhat are the outputs

Output: The average of the input valuesOutput: The average of the input values



Input output relationshipInput output relationship

Input:Input: 3.1 5.3 1.23.1 5.3 1.2

Output:Output: 3.23.2




Input:Input: 8.1 2.2 1.38.1 2.2 1.3

Output:Output: 3.863.86


Devise a solution to the problemDevise a solution to the problemDevise a solution to the problemDevise a solution to the problem

How is the computer to calculate the How is the computer to calculate the average of 3 values?average of 3 values?

Step 1.Step 1. Accept the input values Accept the input values

Computer





Step 2.Step 2. Compute the average Compute the average

ComputerCompute

theAverage




Computethe

Average

Step 3. Step 3. Display the averageDisplay the average





Refine Step 2Refine Step 2




Step 2.1.Step 2.1. Add up the three valuesAdd up the three values

Step 2.2.Step 2.2. Divide the result by 3Divide the result by 3



Refine Step 2.1 Refine Step 2.1 Step 2.1.Step 2.1. Add up the three valuesAdd up the three values

Let “A” denote the first valueLet “A” denote the first value Let “B” denote the second valueLet “B” denote the second value Let “C” denote the third valueLet “C” denote the third value Let “Sum” denote the sum of “A”, “B”, and “C”Let “Sum” denote the sum of “A”, “B”, and “C”

Sum = A + B + C;Sum = A + B + C;



Refine Step 2.2 Refine Step 2.2

Step 2.1.Step 2.1. Divide the result by 3Divide the result by 3

Let “Average” denote the average of “A”,Let “Average” denote the average of “A”,““B” and “C”B” and “C”

Average = Sum / 3.0;Average = Sum / 3.0;


Verify that the solution is correctVerify that the solution is correctVerify that the solution is correctVerify that the solution is correct

A

Step 1.Step 1. Accept the input values, A, B, C Accept the input values, A, B, C

3.9

B 4.1

C 1.3



Step 2.1.Step 2.1. Sum = A + B + C;Sum = A + B + C;

Step 2.2.Step 2.2. Average = Sum /3.0;Average = Sum /3.0;







Step 2.2.Step 2.2. Average = Sum /3.0;Average = Sum /3.0;C

B

A 3.9

4.1

1.3


Sum


Step 3. Step 3. Display the averageDisplay the average9.3




Step 2.2.Step 2.2. Average = Sum /3.0;Average = Sum /3.0;C

B

A 3.9

4.1

1.3








Average

Sum

C

B

A 3.9

4.1

1.3

9.3

3.1








Average

Sum

C

B

A 3.9

4.1

1.3

9.3

3.1

Average is 3.1


Describe the solution using a Describe the solution using a programming languageprogramming language







float A,B,C;float A,B,C;

scanf(“%f”,&A);scanf(“%f”,&A);

scanf(“%f”,&B);scanf(“%f”,&B);

scanf(“%f”,&C);scanf(“%f”,&C);









float A,B,C;float A,B,C;












Sum = A + B + C;Sum = A + B + C;

float A,B,C;float A,B,C;float Sum;float Sum;












Average = Sum / 3.0;Average = Sum / 3.0;

Sum = A + B + C;Sum = A + B + C;

float A,B,C;float A,B,C;float Sum;float Sum;float Average;float Average;












printf(“%f”,Average);printf(“%f”,Average);Average = Sum / 3.0;Average = Sum / 3.0;

Sum = A + B + C;Sum = A + B + C;

float A,B,C;float A,B,C;float Sum;float Sum;float Average;float Average;





Verify that the program does state Verify that the program does state the solution correctlythe solution correctly

Verify that the program does state Verify that the program does state the solution correctlythe solution correctly

Enter the programEnter the program CompileCompile RunRun Compare the output to expected outputCompare the output to expected output


SelectionSelectionSelectionSelection

Facilitates the selection of one of a number Facilitates the selection of one of a number of various alternatives based on a condition.of various alternatives based on a condition.

If the door is openIf the door is open

ThenThenEnter the roomEnter the room

ElseElseKnock at the doorKnock at the door



Accept two integer values and decide whetherAccept two integer values and decide whether or not the larger number is divisible by theor not the larger number is divisible by the smaller numbersmaller number





Input: 2 Integer ValuesInput: 2 Integer Values



Output: YesOutput: Yes


If the larger number is divisibleIf the larger number is divisibleby the second numberby the second number

Output: NoOutput: No If the larger number is not divisibleIf the larger number is not divisibleby the second numberby the second number




Input:Input: 4 24 2

Output:Output: YesYes




Input:Input: 3 123 12

Output:Output: YesYes




Input:Input: 3 73 7

Output:Output: NoNo



How is the computer to decide whetherHow is the computer to decide whether or not the larger number is divisible by theor not the larger number is divisible by the smaller number?smaller number?


Computer



How is the computer to decide whetherHow is the computer to decide whether or not the larger number is divisible by theor not the larger number is divisible by the smaller number?smaller number?

Computethe

result


Step 2.Step 2. Compute and display Compute and display the resultthe result



Refine Step 2. Refine Step 2.

Step 2.Step 2. Compute and display the result Compute and display the result Let “A” denote the first valueLet “A” denote the first value Let “B” denote the second valueLet “B” denote the second value Let “Larger” denote the larger valueLet “Larger” denote the larger value Let “Smaller” denote the smaller valueLet “Smaller” denote the smaller value



Refine Step 2. Refine Step 2.

Step 2.1.Step 2.1. If Larger is divisible by SmallerIf Larger is divisible by Smaller Then print “Yes”Then print “Yes” Otherwise, Larger is not divisibleOtherwise, Larger is not divisible by Smaller and print “No”by Smaller and print “No”

Step 2.Step 2. Compute and display the result Compute and display the result


A


4

B 2

Step 1.Step 1. Accept the input values, A, B Accept the input values, A, B


Smaller

Larger

Step 2.1.Step 2.1. If Larger is divisible byIf Larger is divisible by Smaller Then print “Yes”Smaller Then print “Yes” Otherwise, Larger is notOtherwise, Larger is not divisible by Smaller anddivisible by Smaller and print “No”print “No”




Smaller

Larger

B

A

2

4

2

4Step 2.Step 2. Compute and display the result Compute and display the result





Smaller

Larger

B

A

2

4

2


Output: Output: YesYes



A


3

B 12



Smaller

Larger





Smaller

Larger

B

A

12

12

3






Smaller

Larger

B

A

12

12

3


Output: Output: YesYes



A


3

B 7



Smaller

Larger





Smaller

Larger

B

A

7

7

3






Smaller

Larger

B

A

7

7

3


Output: Output: NoNo








int a,b;int a,b;

scanf(“%d”,&a);scanf(“%d”,&a);

scanf(“%d”,&b);scanf(“%d”,&b);







if (a > b) {if (a > b) {

largest = a;largest = a; smallest = b;smallest = b; }}

else {else { largest = b;largest = b;

smallest = a;smallest = a;}}

int a,b;int a,b;int largest,smallestint largest,smallestscanf(“%d”,&a);scanf(“%d”,&a);

scanf(“%d”,&b);scanf(“%d”,&b);







If (largest % smallest == 0)If (largest % smallest == 0) printf(“Yes”);printf(“Yes”);else else printf(“No”);printf(“No”);

if (a > b) {if (a > b) { largest = a;largest = a;

smallest = b;smallest = b; }}

else {else { largest = b;largest = b;

smallest = a;smallest = a;}}

int a,b;int a,b;int largest,smallestint largest,smallestscanf(“%d”,&a);scanf(“%d”,&a);scanf(“%d”,&b);scanf(“%d”,&b);


IterationIterationIterationIteration

Facilitates the repeated execution of a Facilitates the repeated execution of a segment of the program.segment of the program. While you are hungryWhile you are hungry

Buy a sandwichBuy a sandwich Eat the sandwichEat the sandwich

While you haven’t read the last slideWhile you haven’t read the last slide Read the next slideRead the next slide




Accept an Integer, N as input and print theAccept an Integer, N as input and print the value of 1+ 2+ … + Nvalue of 1+ 2+ … + N




Input: one integer value, NInput: one integer value, N




Output: 1 + 2 + Output: 1 + 2 + …… + N + N




Input:Input: 33

Output:Output: 66




Input:Input: 44

Output:Output: 1010



How is the computer to print the value of How is the computer to print the value of 1+ 2+ … + N1+ 2+ … + N

Step 1.Step 1. Accept the input value Accept the input value

Step 2.Step 2. Compute the sum Compute the sum

Step 3. Step 3. Display the sumDisplay the sum



Refine Step 2Refine Step 2

Step 2.Step 2. Compute the sum Compute the sumStep 2.1.Step 2.1. Sum = 0; Sum = 0;

Step 2.1.Step 2.1. Count = 1; Count = 1; Step 2.3.Step 2.3. Repeat steps 2.3.1 - 2.3.2 N timesRepeat steps 2.3.1 - 2.3.2 N times

Step 2.3.1Step 2.3.1.. Sum = Sum + Count;Sum = Sum + Count;Step 2.3.2Step 2.3.2.. Count = Count +1;Count = Count +1;






N 3

Step 2.1.Step 2.1. Sum = 0; Sum = 0;

Step 2.1.Step 2.1. Count = 1; Count = 1; Step 2.3.Step 2.3. Repeat steps 2.3.1 - 2.3.2 N timesRepeat steps 2.3.1 - 2.3.2 N times

Step 2.3.1Step 2.3.1.. Sum = Sum + Count;Sum = Sum + Count;

Step 2.3.2Step 2.3.2.. Count = Count +1;Count = Count +1;



N 3




Step 2.1.Step 2.1. Sum = 0; Sum = 0;

Step 2.3.Step 2.3. Repeat steps 2.3.1 - 2.3.2 N timesRepeat steps 2.3.1 - 2.3.2 N times


Step 2.1.Step 2.1. Count = 1; Count = 1;




N 3

Sum 0




Step 2.1.Step 2.1. Sum = 0; Sum = 0;







N 3

Sum 0




Step 2.1.Step 2.1. Sum = 0; Sum = 0;





Count 1


Sum 01


N 3




Step 2.1.Step 2.1. Sum = 0; Sum = 0;





Count 1


1

Sum 1

2


N 3




Step 2.1.Step 2.1. Sum = 0; Sum = 0;





Count



N 3

Sum 1




Step 2.1.Step 2.1. Sum = 0; Sum = 0;





Count 2


Sum 13


N 3




Step 2.1.Step 2.1. Sum = 0; Sum = 0;





Count 2


2

Sum 3

3


N 3




Step 2.1.Step 2.1. Sum = 0; Sum = 0;





Count



N 3

Sum 3




Step 2.1.Step 2.1. Sum = 0; Sum = 0;





Count 3


Sum 36


N 3




Step 2.1.Step 2.1. Sum = 0; Sum = 0;





Count 3


3

Sum 6

4


N 3




Step 2.1.Step 2.1. Sum = 0; Sum = 0;





Count



N 3

Sum 6




Step 2.1.Step 2.1. Sum = 0; Sum = 0;





Count 4


Sum 06


N 3




Step 2.1.Step 2.1. Sum = 0; Sum = 0;





Count 4

6








Step 2.1.Step 2.1. Sum = 0; Sum = 0;




int n;int n;

scanf(“%d”,&n);scanf(“%d”,&n);




int sum;int sum;

int n;int n;

sum = 0;sum = 0;





Step 2.1.Step 2.1. Sum = 0; Sum = 0;








count = 1;count = 1;





Step 2.1.Step 2.1. Sum = 0; Sum = 0;




int count;int count;

int n;int n;int sum;int sum;

sum = 0;sum = 0;





While (count <= n){While (count <= n){

}}





Step 2.1.Step 2.1. Sum = 0; Sum = 0;





int sum;int sum;int count;int count;

int n;int n;

sum = 0;sum = 0;





sum = sum+count;sum = sum+count;Step 2.3.1Step 2.3.1.. Sum = Sum + Count;Sum = Sum + Count;




Step 2.1.Step 2.1. Sum = 0; Sum = 0;





}}



int n;int n;

sum = 0;sum = 0;









Step 2.1.Step 2.1. Sum = 0; Sum = 0;



Step 2.3.2Step 2.3.2.. Count = Count +1;Count = Count +1; sum = sum+count; sum = sum+count;

}}




int n;int n;

sum = 0;sum = 0;


count = count +1;count = count +1;




printf(“%d”,sum);printf(“%d”,sum);





Step 2.1.Step 2.1. Sum = 0; Sum = 0;



Step 2.3.2Step 2.3.2.. Count = Count +1;Count = Count +1; sum = sum+count;sum = sum+count; count = count +1;count = count +1;


}}



int n;int n;

sum = 0;sum = 0;


introduction to problem solvings1.2.1 bina © 1998 liran & ofir introduction to problem solving...

Documents

problem solvings1

liran ofir problem

liran ofir steps of

liran ofir introduction

problem algorithm design

average slide

average step

input values step