Algorithm

Algorithm

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  Algorithm o BY :IHTISHAM UL HAQ
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  What is Algorithm? An algorithm is a well-defined procedure that allows a computer to solve a problem.  An algorithm is a sequence of unambiguous instructions. ...
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  Histroy of Algorithm An algorithm (pronounced AL-go-rith-um) is a procedure or formula for solving a problem.  The word derives from the name of the mathematician , Mohammad Ibn-Musa-al-Khwarizmi, who was part of the royal court in Baghdad and who lived from about 780 to 850. Al Khwarizmi’s work is the likely source for the word algebra as well.
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  How to writean algorithm?  Keep in mind that algorithm is a step-by-step process.  Depending upon programming language, include syntax where necessary.  Include variables and their usage.  If they are any loops, try to give sub number lists.  Try to give go back to step number if loop or condition fails.  Use jump statement to jump from one statement to another.
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  How to writean algorithm?  Try to avoid unwanted raw data in algorithm.  Use break and stop to terminate the process.
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  Characteristics of Algorithm The characteristics of a good algorithm are:  Precision – the steps are precisely stated(defined).  Uniqueness – results of each step are uniquely defined and only depend on the input and the result of the preceding steps.  Finiteness – the algorithm stops after a finite number of instructions are executed.
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  Properties of Algorithm An algorithm must have five properties:  Input specified.  Output specified.  Definiteness.  Effectiveness.  Finiteness.
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  Types of Algorithm Algorithm types we will consider include:  Simple recursive algorithms.  Backtracking algorithms.  Divide and conquer algorithms.  Dynamic programming algorithms.  Greedy algorithms.  Branch and bound algorithms.  Brute force algorithms.  Randomized algorithms.
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  Example  Algorithm indaily life.  Algorithm for making a Brownies  Ingredients:  ½ cup butter or margarine.  1 tea spoon vanilla extract .  1 cup sugar.  ½ cup cocoa.  2 eggs .  ½ cup flour. Cont…
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  Example  Procedure:  1.If butter not soft, then melt butter .  2. Blend melted butter and sugar until mixture has creamy consistency.  3. Add eggs and vanilla; stir .  4. Add cocoa and flour; mix until well blended .  5. Pour into greased round glass cake pan.  6. Microwave for 8-9 minutes.  7.Brownies are ready.
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  Example  Algorithm inProgramming.  Write an algorithm to determine a student’s final grade and indicate whether it is passing or failing. The final grade is calculated as the average of four marks.  Pseudocode:  Input a set of 4 marks .  Calculate their average by summing and dividing by 4.  if average is below 50  Print “FAIL”  else  Print “PASS”
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  Example  Detailed Algorithm:  Step 1: Input M1,M2,M3,M4 .  Step 2: GRADE (M1+M2+M3+M4)/4 .  Step 3: if (GRADE < 50)  then  Print “FAIL”  else  Print “PASS”  End if
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  Example  Pseudocode:  Inputthe length in feet (Lft).  Calculate the length in cm (Lcm) by multiplying LFT with 30.  Print length in cm (LCM).
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  Example  Algorithm : Step 1: Input Lft.  Step 2: Lcm Lft x 30.  Step 3: Print Lcm.
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  Thanks