Tag Archives: Sum

Java || Snippet – How To Do Simple Math Using Integer Arrays

This page will consist of simple programs which demonstrate the process of doing simple math with numbers that are stored in an integer array.

REQUIRED KNOWLEDGE FOR THIS SNIPPET

Integer Arrays
The "Random" Class
For Loops
Assignment Operators - Simple Math Operations
Custom Setw/Setfill In Java

Note: In all of the examples on this page, a random number generator was used to place numbers into the array. If you do not know how to obtain data from the user, or if you do not know how to insert data into an array, click here for a demonstration.

===== ADDITION =====

The first code snippet will demonstrate how to add numbers together which are stored in an integer array. This example uses the “+=” assignment operator.


QUICK NOTES:
The highlighted lines are sections of interest to look out for.

The code is heavily commented, so no further insight is necessary. If you have any questions, feel free to leave a comment below.

SAMPLE OUTPUT

Welcome to My Programming Notes' Java Program.

Original array values:
22 26 41 89 35 90 15 99 85 5 95 86
--------------------------------------------------
The sum of the items in the array is: 688

===== SUBTRACTION =====

The second code snippet will demonstrate how to subtract numbers which are stored in an integer array. This example uses the “-=” assignment operator.


QUICK NOTES:
The highlighted lines are sections of interest to look out for.

The code is heavily commented, so no further insight is necessary. If you have any questions, feel free to leave a comment below.

SAMPLE OUTPUT

Welcome to My Programming Notes' Java Program.

Original array values:
99 92 91 26 1 52 98 62 51 22 64 65
--------------------------------------------------
The difference of the items in the array is: -723

===== MULTIPLICATION =====

The third code snippet will demonstrate how to multiply numbers which are stored in an integer array. This example uses the “*=” assignment operator.


QUICK NOTES:
The highlighted lines are sections of interest to look out for.

The code is heavily commented, so no further insight is necessary. If you have any questions, feel free to leave a comment below.

SAMPLE OUTPUT

Welcome to My Programming Notes' Java Program.

Original array values:
95 63 32 19 93 83 71 35 32 37 66 95
--------------------------------------------------
The product of the items in the array is: 494770176

===== DIVISION =====

The fourth code snippet will demonstrate how to divide numbers which are stored in an integer array. This example uses the “/=” assignment operator.


QUICK NOTES:
The highlighted lines are sections of interest to look out for.

The code is heavily commented, so no further insight is necessary. If you have any questions, feel free to leave a comment below.

SAMPLE OUTPUT

Welcome to My Programming Notes' Java Program.

Original array values:
28 85 90 52 1 64 93 85 4 22 4 28
--------------------------------------------------
The quotient of the items in the array is: 1.8005063061510687E-17

C++ || Snippet – How To Do Simple Math Using Integer Arrays

This page will consist of simple programs which demonstrate the process of doing simple math with numbers that are stored in an integer array.

REQUIRED KNOWLEDGE FOR THIS SNIPPET

Integer Arrays
For Loops
Assignment Operators - Simple Math Operations
Setw

Note: In all of the examples on this page, a random number generator was used to place numbers into the array. If you do not know how to obtain data from the user, or if you do not know how to insert data into an array, click here for a demonstration.

===== ADDITION =====

The first code snippet will demonstrate how to add numbers together which are stored in an integer array. This example uses the “+=” assignment operator.


QUICK NOTES:
The highlighted lines are sections of interest to look out for.

The code is heavily commented, so no further insight is necessary. If you have any questions, feel free to leave a comment below.

SAMPLE OUTPUT

Original array values
64 85 44 31 35 2 94 67 12 80 97 10
--------------------------------------------------------
The sum of the items in the array is: 621

===== SUBTRACTION =====

The second code snippet will demonstrate how to subtract numbers which are stored in an integer array. This example uses the “-=” assignment operator.


QUICK NOTES:
The highlighted lines are sections of interest to look out for.

The code is heavily commented, so no further insight is necessary. If you have any questions, feel free to leave a comment below.

SAMPLE OUTPUT

Original array values
10 43 77 10 2 17 87 67 6 95 57 18
--------------------------------------------------------
The difference of the items in the array is: -489

===== MULTIPLICATION =====

The third code snippet will demonstrate how to multiply numbers which are stored in an integer array. This example uses the “*=” assignment operator.


QUICK NOTES:
The highlighted lines are sections of interest to look out for.

The code is heavily commented, so no further insight is necessary. If you have any questions, feel free to leave a comment below.

SAMPLE OUTPUT

Original array values
33 36 52 28 4 99 97 17 42 81 83 33
--------------------------------------------------------
The product of the items in the array is: 1803759104

===== DIVISION =====

The fourth code snippet will demonstrate how to divide numbers which are stored in an integer array. This example uses the “/=” assignment operator.


QUICK NOTES:
The highlighted lines are sections of interest to look out for.

The code is heavily commented, so no further insight is necessary. If you have any questions, feel free to leave a comment below.

SAMPLE OUTPUT

Original array values
75 38 59 14 53 42 29 88 92 27 69 16
--------------------------------------------------------
The quotient of the items in the array is: 2.72677e-020

C++ || Input/Output – Find The Average of The Numbers Contained In a Text File Using an Array/Bubble Sort

This program highlights more practice using text files and arrays. This program is very similar to one which was previously discussed on this site, but unlike that program, this implementation omits the highest/lowest values which are found within the array via a sort.

The previously discussed program works almost as well as the current implementation, but where it fails is when the data which is being entered into the program contains multiple values of the same type. For example, using the previously discussed method to obtain the average by omitting the highest/lowest entries found within an array, if the array contained the numbers:

1, 2, 3, 3, 3, 2, 2, 1

The previous implementation would mark 1 as being the lowest number (which is correct) and it would mark 3 as being the highest number (which is also correct). The area where it fails is when it omits the highest and lowest scores found within the array. The program will skip over ALL of the numbers contained within the array which equal to 1 and 3, thus resulting in the program obtaining the wrong answer.

To illustrate, before the previous program computes its adjusted average scores, it will not only omit just 1 and 3 from the array, but it will also omit all of the 1’s and 3’s from the list, resulting in our array looking like this:

2, 2, 2

When you are finding the average of a list of numbers by omitting the highest/lowest scores, you don’t want to omit ALL of the values which may equal said numbers, but merely just the highest (last element in the array) and lowest (first element in the array) scores.

So if the previous implementation has subtle issues, why is it on this site? The previous program illustrates very well the process of finding the highest/lowest integers found within an array. It also works flawlessly for data in which there is non repeating values found within a list (i.e 1,2,3,4,5,23,6). So if you know you are reading in from a file in which there are non repeating values, the previous implementation works well. Often times though, developers do not know what type of data the incoming files will contain, so this current implementation is a better way to go, especially if it is not known exactly how many numbers are contained within a file.

REQUIRED KNOWLEDGE FOR THIS PROGRAM

Fstream
Ifstream
Ofstream
Working With Files
While Loops
For Loops
Bubble Sort
Basic Math - Finding The Average

The data file that is used in this example can be downloaded here.

Note: In order to read in the data .txt file, you need to save the .txt file in the same directory (or folder) as your .cpp file is saved in. If you are using Visual C++, this directory will be located in

Documents > Visual Studio 2010 > Projects > [Your project name] > [Your project name]

NOTE: On some compilers, you may have to add #include < cstdlib> in order for the code to compile.


QUICK NOTES:
The highlighted lines are sections of interest to look out for.

The code is heavily commented, so no further insight is necessary. If you have any questions, feel free to leave a comment below.

Once compiled, you should get this as your output
(Remember to include the input file)

The numbers countained in the input file are: 12, 45, 23, 46, 11, -5, 23, 33, 50, 17, 13, 25, 15, 50,
The highest and lowest numbers contained in the file are:
Highest: 50
Lowest: -5

The average of the 14 numbers contained in the file is: 25.5714
The average of the 14 numbers contained in the file omitting the highest and lowest scores is: 26.0833

C++ || Find The Average Using an Array – Omit Highest And Lowest Scores

This page will consist of two programs which calculates the average of a specific amount of numbers using an array.

REQUIRED KNOWLEDGE FOR BOTH PROGRAMS

Float Data Type
Constant Values
Arrays
For Loops
Assignment Operators
Basic Math

====== FIND THE AVERAGE USING AN ARRAY ======

The first program is fairly simple, and it was used to introduce the array concept. The program prompts the user to enter the total amount of numbers they want to find the average for, then the program displays the answer to them via cout.


QUICK NOTES:
The highlighted lines are sections of interest to look out for.

ARRAY
Notice the array declaration on line #9. The type of array being used in this program is a static array, which has the ability to store up to 100 integer elements in the array. You can change the number of elements its able to store to a higher or lower number if you wish.

FOR LOOP
Notice line 17-22 contains a for loop, which is used to actually store the data inside of the array. Without some type of loop, it is virtually impossible for the user to input data into the array; that is, unless you want to add 100 different cout statements into your code asking the user to input data. Line 21 uses the assignment operator “+=” which gives us a running total of the data that is being inputted into the array. Note the loop only stores as many elements as the user so desires, so if the user only wants to input 3 numbers into the array, the for loop will only execute 3 times.

Once compiled, you should get this as your output:

How many numbers do you want to find the average for?: 5
Enter #1 : 23
Enter #2 : 17
Enter #3 : 29
Enter #4 : 14
Enter #5 : 16
The average of the 5 numbers is 19.8


====== FIND THE AVERAGE – OMIT HIGHEST AND LOWEST SCORES ======

The second program is really practical in a real world setting, specifically when a teacher records test scores into the computer. We were asked to create a program for a fictional competition which had 6 judges. The 6 judges each gave a score of the performance for a competitor in a competition, (i.e a score of 1-10), and we were asked to find the average of those scores, omitting the highest/lowest results. The program was to store the scores into an array, display the scores back to the user via cout, display the highest and lowest scores among the 6 obtained, display the average of the 6 scores, and finally display the average adjusted scores omitting the highest and lowest result.


QUICK NOTES:
The highlighted lines are sections of interest to look out for.

CONST
A constant variable was declared and used to initialize the array (line 8). Note, when using static arrays, the program has to know how many elements to initialize the program with before the program starts, so creating a constant variable to do that for us is convenient.

FOR LOOPS
Once again loops were used to traverse the array, as noted on lines 16, 23, 30, 53, and 70. The const variable was also used within the for loops, making it easier to modify the code if its necessary to reduce or increase the number of available judges.

HIGHEST/LOWEST SCORES

This is noted on lines 34-44, and it is really simple to understand the process once you see the code.

OMITTING HIGHEST/LOWEST SCORE

Lines 70-78 highlight this process, and the loop basically traverses the array, skipping over the highest/lowest elements

Once compiled, you should get this as your output:

Judges, enter one score each for
the current competitor: 123 453 -789 2 23345 987

These are the scores from the 6 judges:
The score for judge #1 is: 123
The score for judge #2 is: 453
The score for judge #3 is: -789
The score for judge #4 is: 2
The score for judge #5 is: 23345
The score for judge #6 is: 987

These are the highest and lowest scores:
Highest: 23345
Lowest: -789
The average score is: 4020.17
The average adjusted score omitting the highest and lowest result is: 391.25

C++ || Input/Output Text File Manipulation – Find Highest, Lowest, Average & Total Sum

This is a program which will utilize fstream, specifically ifstream and ofstream, to read in data from one .txt file, and it will then output selected data into an entirely new separate .txt file.

The input data file has 8 different rows, with each row containing 7 numbers on each line. The program will take in each line one at a time, manipulating the 7 numbers to receive the desired output. This program will find the highest/lowest number in each selected line, along with the total sum of all the numbers contained in that line, and the average of all the numbers. So at the end of the program, There will be 8 different sets of data compiled for each row, with the output file looking like this:

SAMPLE RUN:

- Input File -
3 5 7 3 4 5 6

- Output File -
The dataset for input line #1 is: 3 5 7 3 4 5 6
The highest number is: 7
The lowest number is: 3
The total of the numbers is: 33
The average of the numbers is: 4.71

The data file that is used in this example can be downloaded here

Note: In order to read in the data .txt file, you need to save the .txt file in the same directory (or folder) as your .cpp file is saved in. If you are using Visual C++, this directory will be located in

Documents > Visual Studio > Projects > [Your project name] > [Your project name]

NOTE: On some compilers, you may have to add #include < cstdlib> in order for the code to compile.


QUICK NOTES:
The highlighted lines are sections of interest to look out for.

LOOPS
This program utilizes one do/while loop on lines 39-97 which loops thru the input file until it reaches the end of the file. This program also uses a for loop, which is noted on line 46.

CALCULATING THE SUM
Line 50 contains the assignment operator “+=“, which will calculate a running total for all the values of each selected line.

READING IN DATA FROM FILE
This is noted in line 48, and works just like a cin statement.

OPENING FILES
File declarations, and the opening of files are highlighted on lines: 14-15, 24-25, 32-33. On line 32, the term “ios::app” means the file will append new data to the text file, instead of overwriting the old data contained within that file.

OUTPUT DATA TO FILE
This is highlighted on lines 80-84, and as you can see, the output statements are exactly the same as cout statements.

CLOSE FILES
Remember to close the files you open, as highlighted on lines 101 and 102.

Once compiling the above code, you should receive this as your output (for the 8 selected lines contained within the input text file)

The dataset for input line #1 is: 346 130 982 90 656 117 595
The highest number is: 982
The lowest number is: 90
The total of the numbers is: 2916
The average of the numbers is: 416.571

The dataset for input line #2 is: 415 948 126 4 558 571 87
The highest number is: 948
The lowest number is: 4
The total of the numbers is: 2709
The average of the numbers is: 387

The dataset for input line #3 is: 42 360 412 721 463 47 119
The highest number is: 721
The lowest number is: 42
The total of the numbers is: 2164
The average of the numbers is: 309.143

The dataset for input line #4 is: 441 190 985 214 509 2 571
The highest number is: 985
The lowest number is: 2
The total of the numbers is: 2912
The average of the numbers is: 416

The dataset for input line #5 is: 77 81 681 651 995 93 74
The highest number is: 995
The lowest number is: 74
The total of the numbers is: 2652
The average of the numbers is: 378.857

The dataset for input line #6 is: 310 9 995 561 92 14 288
The highest number is: 995
The lowest number is: 9
The total of the numbers is: 2269
The average of the numbers is: 324.143

The dataset for input line #7 is: 466 664 892 8 766 34 639
The highest number is: 892
The lowest number is: 8
The total of the numbers is: 3469
The average of the numbers is: 495.571

The dataset for input line #8 is: 151 64 98 813 67 834 369
The highest number is: 834
The lowest number is: 64
The total of the numbers is: 2396
The average of the numbers is: 342.286

We have reached the end of the file!