The document discusses algorithms and flowcharts for conditional and iterative problems. It provides examples and solutions for writing algorithms and flowcharts to determine voter eligibility based on age, print all natural numbers from 1 to N, and find the biggest of two or three numbers. It also includes practice problems for students to write algorithms and flowcharts to solve problems related to discounts based on order quantity and calculating the sum of two numbers using functions. The document aims to help students understand how to design algorithms and flowcharts for conditional and iterative problems.

1. SESSION NUMBER: 02
Session Outcome: At the end of this session on ALGORITHMS AND FLOWCHARTS, Students will be able:
1. To design algorithms for conditional problems.
2. To design flowcharts for iterativeproblems.
Ex 1. Write an algorithmanddraw flowchart to findwhetherpersoniseligibleforvote ornot(above
18 eligible).
Solution:
1. Identifythe inputstobe giventovoteEligibilityfunction ( here itisage )
2. Identifythe outputtobe printedonmonitor (here itis Eligible ornotEligible)
Algorithmfor main() function:
Step1: Start
Step2: age:=20
Step3: Call voteEligibility(age) function
Step4: Stop
Algorithmfor voteEligibility(intage) function:
Step1: Start
Step2: if( age >= 18) then
print“Eligible to Vote”
Step3: else
print“Not eligible toVote”
Step4: returnto main()

2. Flowchart:
Code:
#include<stdio.h> // headerfile
voidVoteEligibility(int); // functionprototype
intmain()
{
intage;
age = 20;
voteEligibility(age); // functioncall
return0;
}
voidvoteEligibility(intage) //functionbodybeginshere
{
if(age>=18)
{
printf("Eligibletovote");
}
else
{
printf("NotEligible tovote");
}
return;
}
Here in the above
program,we have to
write #include<stdio.h>
stdioisthe short formfor standardinputand output
stdio.hisan headerfile.
A headerfile containsmanyfunctions.
Some of the available functionsinheaderfilestdio.hare printf,scanf,etc.
// are comments. Commentswill enable youtounderstandthe code.Whateveryouwrite after//are not

3. executedbythe compiler.
intmain() Executionof Cprogram starts frommain() andit isan inbuiltmethod
voidVoteEligibility(int); Functionprototype indicatesthe returntype of function, functionname,inputparameters
and theirdatatypes
intage; a memoryisallocatedandname giventomemorylocationisage. Here age iscalleda
variable.A namedmemorylocationiscalledavariable
intis a data type indicatingthatwe can store integervaluesinage memorylocation.
The range of valuesthatcan be storedinan integervariable,age is -32767 to 32768 in a 32-
bitcomputer
age=20; will putvalue 20 inthe age memorylocation.
voteEligibility(age); main() callsthe function voteEligibility(age); main() pausesexecution
CPU starts executingVoteEligibility(age);function
voidvoteEligibility(intage)
{
The userdefinedfunctionvoteEligibility(intage) isgivenfunctionalityhere.Itiscalleduser
definedfunctionas thisfunctioniswrittenbyprogrammer.Butprintf()functioniscalled
inbuiltfunctionasthe code forprintf() iswrittenbysome one else andwe are usingit.
{ indicate the functionbeginshere,inotherwords,the functionblockbeginsher
if(age>=18)
{
If is an conditional statementasitchecksa conditionage >= 18. if the conditionistrue
then{ indicatesbeginningof if block.all the statementsinside{ and} of if blockwill be
executed
Alsohere age referstothe valuespresentinage memorylocation.
If is a keywordasit has some special meaning
printf("Eligibletovote");
}
printf will printthe message “Eligible tovote”onthe monitor.
} indicatesendof if block
printf isan inbuiltfunctioninstdio.h
else
{
else mustbe writtenafterthe if blockandwill be executedif the conditionage>=18
becomesfalse.i.e,the value insideage memorylocationisnotgreaterthan18 thenelse
blockwill execute
else isalsoa keyword

4. printf("Eligibletovote");
}
All the statementsinside else blockwill be executedif the conditionage>=18 isfalse
return will enable youtocome outof the voteEligibilityfunctionandreturntothe main() where
thisfunctionwascalled
} End of voteEligibility functionblock
return0; main() functionreturns0to compilerindicatingthe programexecutedsuccessfully
} End of main() function

5. Example 2:
Use an algorithmtoprintall natural numbersfrom1 to N to make the studentsunderstanddesignof
algorithmsandflowchartfor iterative problems.
Solution:
1. Identifythe inputstobe giventoPrintmethod( here itis n)
2. Identifythe outputtobe printedonmonitor(all natural numbersfrom1 to n)
Algorithmfor main() function:
Step1: Start
Step2: n:=20
Step3: Call Print(n) function
Step4: Stop
Algorithmfor Print(n) function:
Step1: Start
Step2: i := 1
Step3: if ( i <= n) then
Step3.1 : printi
Step3.2: i := i+1
Step3.3: go to step3
Step4: returnto main()
Flowchart:
main() print(intn)
Here the main() methodpausesandthe CPU control goesto print(intn)
Here the CPU control goesback to main()
Start
n := 20
Print(n)
Stop
Print(intn)
i <= n
print i
i := 1
i := i+1
True
False

6. Code:
#include<stdio.h>
voidPrint(int);
intmain()
{
intn=20;
Print(n);
return0;
}
voidPrint(intn)
{
inti = 1;
while(i<=n)
{
printf("%d",i);
i=i+1;
}
}

7. Practice SessionProblems:
Q1) Write an algorithmanddraw flowchart tofind biggestof giventwonumber.
Algorithmfor main() function:
Step1: Start
Step2: n1:=10
Step3: n2 := 20
Step4: biggest_number:=calculateBig(n1,n2)
Step5: printbiggest_number
Step6: Stop
Algorithmfor calculateBig(intn1, int n2) function:
Step1: Start
Step2: if( n1 >= n2) then
big:= n1
Step3: else
big:= n2
Step4: returnbig
FlowChart:

8. Q2) Write an algorithmanddraw flowchart tofindthe biggestof given3 distinctnumbers.
Algorithmfor main() function:
Step1: Start
Step2 : n1 := 10
Step3 : n2 := 20
Step4 : n3 := 30
Step5: ans=calculateBig(n1,n2,n3)
Step6: printans
Step7: Stop
Algorithmfor calculateBig(intn1, int n2, int n3) function:
Step1: Start
Step2 : if n1 > n2 then
Step2.1: if n1 > n3 then
big:= n1
Step2.2: else
big:= n3
Step3: else
Step3.1 if n2 > n3 then
big:= n2
Step3.2 else
big:= n3
Step4: returnbig
Flowchart:

9. Q3) Draw flowchart & write algorithm to print the discount applicable to the given order quantity.
Vishnu Limited calculates discounts allowed to customers on the following basis
Orderquantity Normal
discount
1-99 5%
100-199 7%
200-499 9%
500 andabove 10%
FlowChart:

10. To get to knowaboutmemoryallocationtovariables,Considerthe below example.
Q) Write an algorithmtofindsumof twonumbersusingfunctions.
Solution:
1. Identifythe inputstobe giventoSum() method
2. Identifythe outputtobe printedonmonitor
1. Executionof C program startsfrom main()
2. main() callssum() andgives3,4 valuestosum()
3. sum() methodcomputessumof 3 and 4 and returnsto main().
4. main() will printthe outputtothe monitor