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3.3: Case Study- Find the Largest Number

  • Page ID
    126506
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    Find the programming solution of following problem:

    Use only two variables to write a C++ program that asks a user to enter 5 integers and then display the largest number that the user entered.

    When we run this program, we should have following outputs:

    Image 3-3-1.png

    Now, let's code the program:

    First, we declare two integer variables a and largest in line 7, and then, in line 8 and line 9, let a user to enter the first integer and assign this integer to the variable largest using a cin statement:

    Image 3-3-2.png

    Now, we use a cin statement, in line 10 to let the user to enter the second integer and assign it to the variable a:

    Image 3-3-3.png

    This time, we compare the values of the variable largest and the variable a, if the value of the variable a is greater than the value of the variable largest, assign the value of a to the variable largest, otherwise, do nothing:

    Image 3-3-4.png

    Now, in line 14, we use a cin again to let the user to enter the third integer and assign it to the variable a. Then, compare the third integer the user entered with the value of the variable largest by using another if statement. If the third number is greater than the value of the largest, replace the value of the variable largest by the third number, otherwise, do nothing:

    Image 3-3-5.png

    Please note: at this point, the variable largest is holding the largest of first three numbers user entered. Now, we repeat the code from line 10 to line 13 two more times:

    Image 3-3-6.png

    Because each time, we replace the value of the variable largest with a larger integer user entered, the variable largest will always hold the largest of the numbers user entered. After the program receives five integers, the value of the variable largest is the largest number user entered. Thus we use a cout statement to display it on the output screen:

    Image 3-3-7.png


    This page titled 3.3: Case Study- Find the Largest Number is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by Jin He.

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