Algorithms

What is an algorithm?

Algorithm can be defined as step by step procedure to solve a given problem by using a computer system to get desired result. It includes finite number of steps in hierarchical order from start to stop.

Characteristics of algorithm:
1. It should be unambiguous (no doubts).
2. It should not have any uncertainty steps.
3. It should generate correct result.

Examples.
Algorithm to check for palindrome.

Step1: Start

Step2: Read a number i.e. num

Step3: dup=num

Step4: while  (num!=0)
            rem=num%10
            rev=(rev*10)+rem
            num=num/10

Step5: Print reversed number i.e. rev

Step6:  if (rev==dup)
            Display "Plaidrome"
            else
            Display "Not Palidrome"
         
Step7 : Stop

Algorithm to generate electricity bill

Step1: Start

Step2:  Read user name and number of units consumed i.e. name, units

Step3: if (units<=200) goto next step; otherwise goto step 5

Step4: amt=units*0.80 and goto step

Step5: if (units<=300) then goto next step; otherwise goto step 7

Step6: amt=160+((units-200)*0.90) and goto step 8

Step7: amt=250+((units-300)+1) and goto next step

Step8: total_amt=amt+100

Step9: if (total_amt>400) goto next step; otherwise goto step 11

Step10: sur_charge=total_amt*0.15, total_amt=total_amt+sur_charge

Step11: Print name and total_amt

Step12: Stop