Basic Algorithm @PPSC(1)

Basic Algorithm @PPSC(1)

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  ALGORITHM Presented by Amiya BhusanBagjadab Asst. Prof., Department of CSE, Radhakrisna Institute of Technology and Engineering(RITE)
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  Contents  Introduction  Characteristicsof an Algorithm  Algorithm development process  Basic Steps For Designing Algorithm  Some Examples
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  Introduction  An algorithmis a sequence of unambiguous instructions for solving a problem, i.e., for obtaining a required output for any legitimate input in a finite amount of time.  Algorithm is a step-by-step procedure, which defines a set of instructions to be executed in a certain order to get the desired output.  Algorithm is any well defined computational procedure that takes some value or set of values as input and produces some value or set of values as output.
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  Characteristics of anAlgorithm  Unambiguous − Algorithm should be clear and unambiguous. Each of its steps (or phases), and their inputs/outputs should be clear and must lead to only one meaning.  Input − An algorithm should have 1 or more well-defined inputs.  Output − An algorithm should have 1 or more well-defined outputs, and should match the desired output.  Finiteness − Algorithms must terminate after a finite number of steps.  Feasibility − Should be feasible with the available resources.  Independent − An algorithm should have step-by-step directions, which should be independent of any programming code.
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  Algorithm development process Our algorithm development process consists of five major steps. Step 1: Obtain a description of the problem. Step 2: Analyze the problem. Step 3: Develop a high-level algorithm. Step 4: Refine the algorithm by adding more detail. Step 5: Review the algorithm.
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  Basic Steps ForDesigning Algorithm  Step 1 − START  Step 2 −Take Input Variables  Step 3 −Develop Logics  Step 4 − Print the Output  Step 5 − STOP
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  Design an algorithmto add two numbers and display the result.  Step 1 − START  Step 2 − declare three integers a, b & c  Step 3 − define values of a & b  Step 4 − add values of a & b  Step 5 − store output of step 4 to c  Step 6 − print c  Step 7 − STOP
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  Find the largestnumber among three different numbers  Step 1: Start  Step 2: Declare variables a,b and c.  Step 3: Read variables a,b and c.  Step 4: If a > b If a > c Display a is the largest number. Else Display c is the largest number. Else If b > c Display b is the largest number. Else Display c is the greatest number. Step 5: Stop
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  Factorial of anumber entered by the user.  Step 1: Start  Step 2: Declare variables n, factorial and i.  Step 3: Initialize variables factorial ← 1 i ← 1  Step 4: Read value of n  Step 5: Repeat the steps until i = n 5.1: factorial ← factorial*i 5.2: i ← i+1 Step 6: Display factorial Step 7: Stop
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  Check whether anumber is a prime number or not  Step 1: Start  Step 2: Declare variables n, i, flag.  Step 3: Initialize variables flag ← 1 i ← 2  Step 4: Read n from the user.  Step 5: Repeat the steps until i=(n/2) 5.1 If remainder of n÷i equals 0 flag ← 0 Go to step 6 5.2 i ← i+1 Step 6: If flag = 0 Display n is not prime else Display n is prime Step 7: Stop