Example Programming Algorithm, Pseudocode, Flowchart

ILLUSTRATIVE PROBLEM

1. Guess an integer in a range

Algorithm:

Step1: Start

Step 2: Declare hidden, guess

Step 3: Compute hidden= Choose a random value in a range

Step 4: Read guess

Step 5: If guess=hidden, then

Print Guess is hit

Else

Print Guess not hit

Print hidden

Step 6: Stop

Pseudocode:

BEGIN

COMPUTE hidden=random value in range

READ guess

IF guess=hidden, then

PRINT Guess is hit

ELSE

PRINT Guess not hit

PRINT hidden

END IF-ELSE

END

Flowchart:

2. Find minimum in a list

Algorithm:

Step 1: Start

Step 2: Read n

Step 3:Initialize i=0

Step 4: If i<n, then goto

step 4.1, 4.2 else goto

step 5 Step4.1: Read a[i]

Step 4.2: i=i+1 goto step 4

Step 5: Compute min=a[0]

Step 6: Initialize i=1

Step 7: If i<n, then go to step 8 else goto step 10

Step 8: If a[i]<min, then goto

step 8.1,8.2 else goto 8.2

Step 8.1: min=a[i]

Step 8.2: i=i+1 goto 7

Step 9: Print min

Step 10: Stop

Pseudocode:

BEGIN READ n

FOR i=0 to n, then

READ a[i]

INCREMENT i

END FOR

COMPUTE min=a[0]

FOR i=1 to n, then

IF a[i]<min, then

CALCULATE min=a[i]

INCREMENT i

ELSE

INCREMENT i

END IF-ELSE

END FOR

PRINT min

END

Flowchart:

3. Insert a card in a list of sorted cards

Algorithm:

Step 1: Start

Step 2: Read n

Step 3:Initialize i=0

Step 4: If i<n, then goto step 4.1, 4.2 else goto step 5

Step4.1: Read a[i]

Step 4.2: i=i+1 goto step 4

Step 5: Read item

Step 6: Calculate i=n-1

Step 7: If i>=0 and item<a[i], then go to step 7.1, 7.2 else goto step 8

Step 7.1: a[i+1]=a[i]

Step 7.2: i=i-1 goto step 7

Step 8: Compute a[i+1]=item

Step 9: Compute n=n+1

Step 10: If i<n, then goto step 10.1, 10.2  lse goto st 11

Step10.1: Print a[i]

Step10.2: i=i+1 goto step 10

Step 11: Stop

Pseudocode:

BEGIN

READ n

FOR i=0 to n, then

READ a[i]

INCREMENT i

END FOR

READ item

FOR i=n-1 to 0 and item<a[i], then

CALCULATE a[i+1]=a[i]

DECREMENT i

END FOR

COMPUTE a[i+1]=a[i]

COMPUTE n=n+1

FOR i=0 to n, then

PRINT a[i]

INCREMENT i

END FOR

END

Flowchart:

4. Tower of Hanoi

Algorithm:

Step 1: Start

Step 2: Read n

Step 3: Calculate move=pow(2,n)-1

Step 4: Function call T(n,Beg,Aux,End) recursively until n=0

Step 4.1: If n=0, then goto

step 5 else goto step

4.2 Step

4.2: T(n-1,Beg,End,Aux) T(1,Beg,Aux,End) , Move disk from source to desti ation T(n-1,Aux,Beg,End)

Step 5: Stop

Pseudcode:

BEGIN

READ n

CALCULATE move=pow(2,n)-1

FUNCTION T(n,Beg,Aux,End) Recursiv ly until n=0

PROCEDURE

IF n=0 then,

No disk to move

Else

T(n-1,Beg,End,Aux)

T(1,Beg,Aux,End), move  isk from source to destination

T(n-1,Aux,Beg,En )

END PROCEDURE

END

Flowchart:

Procedure to solve Tower of Hanoi

The goal of the puzzle is to move all the disks from leftmost peg to rightmost peg.

1.        Move only one disk at a time.

2.        A larger disk may not be p1aced on top of a smaller disk. For example, consider n=3 disks