Question

Write a complete C++ program that reads students names and their test scores from an input text file. The program should output each student’s name followed by the test scores and the relevant grade in an output text file. It should also find and display on screen the highest/lowest test score and the name of the students having the highest/lowest test score, average and variance of all test scores.

Student data obtained from the input text file should be stored in a structure of type studentType, which has four components: studentFName and studentLName of type string, testScore of type int (testScore is between 0 and 100), and grade of type char. Suppose that the class has 25 students. Use an array of 25 components of type studentType. [Hint: The input text file should consist of 25 records].

Your program must contain the following functions:

1. A function to read the students data (i.e. Names & test scores) from text file into an array
2. A function to write student data (i.e. Names, test scores, and grades) from the array to a text file.
3. A function to assign the relevant grade to each student.
4. A function to find the highest test score.
5. A function to find the lowest test score.
6. A function to find the average for all test scores.
7. A function to find the variance of test scores.
8. A function to print the names of student having the highest test score.
9. A function to print the names of student having the lowest test score

The variance is calculated as follows:

Variance = ∑( X_i – X_Avg )² / N

Where;

∑ = Summation

X_i = Each value in array

X_Avg = Average

N = The number of elements in array

[Note: The variance is obtained by subtracting the average from each value in the array, squaring the values obtained, adding them, and dividing by the number of elements in the array.]

Your program must output each student’s name in this form: last name followed by a comma, followed by a space, followed by the first name.

Answer 1

I have implemented the program as per the requirements given above. Please find the following Code Screenshot, Output, and Code.

ANY CLARIFICATIONS REQUIRED LEAVE A COMMENT.

PLEASE REMEMBER TO CREATE A INPUT FILE WITH 25 ENTRIES AS MENTIONED IN THE TASK OR COPY THE FILE AT THE END OF THE POST

1.CODE SCREENSHOT:

1 StudentGrades.cpp X #include <iostream> 2 #include <string> 3 #include <fstream> 4 #include <iomanip> 5 using namespace std; 6 struct Student 7 { 8 string student FName; 9 string studentLName; 10 int testscore; 11 char grade; 12 - }; 13 /*A function to read the students data (i.e. Names & test scores) from text file into an array*/ 14 &void readData(ifstream& in, Student S[], int size) { 15 int n=0; 16 while (n<size) { 17 in>>s [n].studentLName>>s[n].student FName>>s [n].testscore; 18 n++; 19 20 - } } 21 /* 22 23 24 25 26 27 LA function to write student data (i.e. Names, test scores, and grades) from the array to a text file. */ şvoid writeData (ofstream& out, Student s[l,int size) { int n=0; while (n<size) { out<<s[n].studentLName<<", "<<s[n].student FName<<" "<<s[n].testscore<<endl; n++;

ܝܟ StudentGrades.cpp 28 29 -} 30 //A function to assign the relevant grade to each student. 31 şvoid assignGrades (Student s[], int size) { 32 int i; 33 for(i=0;i<size;i++) 34 if (s[i].testscore<60) 35 s[i].grade='F'; 36 else if (s[i].testscore<70) 37 S[i].grade='D'; 38 else if (s[i].testscore<80) 39 s[i].grade='c'; 40 else if (s[i].testscore<90) 41 s[i].grade='B'; 42 else 43 s[i].grade='A'; 44. - } 45 /*A function to find the highest test score. */ 46 çint findHighest score (const student s[], int size) { 47 int high=0,i; 48 for(i=0;i<size; i++) 49 if (high < s[i].testScore ) 50 high=s[i].testscore; 51 return high; 52 5

J7 J7 J7 J7 ܝܟ StudentGrades.cpp X 53 /*A function to find the lowest test score. */ 54 gint findLowestscore (const Student S[], int size) { 55 int low=100,i; 56 for(i=0;i<size;i++) 57 if (low > s[i].testscore ) 58 low=s[i].testscore; 59 return low; 60 61 /*A function to find the average for all test scores. */ 62 double calculateAverage (const Student S[], int size) { 63 double sum=0; 64 int i; 65 for(i=0;i<size;i++) 66 sumurs[i].test score; 67 return sum/size; 68 69 70 /*A function to find the variance of test scores*/ 71 gint calculateVariance (const student s[], int size) { 72 double sum=0, avg=0,v=0; 73 int i; 74 avg=calculateAverage (s,size); 75 for(i=0;i<size;i++) { 76 v+=(s[i].testscore-avg) * (s[i].testscore-avg); 77 78 return v/size; 79 - } } }

} StudentGrades.cpp X 80 /*A function to print the names of student having the highest test score. */ 81 void printHighest score (const Student s[], int size) { 82 int high=0, i,hi=-1; 83 for(i=0;i<size;i++) 84 A if (high < s[i].test Score ) { 85 high=s[i].test Score; 86 hiri; 87 88 cout<<"Highest Test Score: "<<high<<endl; 89 cout<<"Students having the highest test score: "<<s[hi].studentLName<<", "<<s [hi].student FName<<endl; 90 91 } 92 /*A function to print the names of student having the lowest test score* / 93 şvoid printLowestscore (const Student s[], int size) { 94 int low=100,i,li=-1; 95 for(i=0;i<size;i++) 96 if (low > s[i].testscore ) { 97 low=s[i].test score; 98 liri; 99 100 cout<<"Highest Test Score: "<<low<<endl; 101 cout<<"Students having the Lowest test score: "<<s[li].studentLName<<", "<<s[li].student FName<<endl; 102 103 ܝܟ }

} } StudentGrades.cpp X 104 şvoid print (const Student s[], int size) { 105 cout<<left<<setw(30) <<"Student Name"<<right<<setw(20)<<"Testscore"<<right<<setw(7) <<"Grade"<<endl; 106 string name; 107 int high,i; 108 for(i=0;i<size; i++) { 109 name=s[i].studentLName+", "+s[i].student FName; 110 cout<<left<<setw(30) <<name<<right<<setw(20) <<s[i].testScore<<right<<setw(7) <<s[i].grade<<endl; 111 112 cout<<endl; 113 114 Fint main() { 115 ifstream in; 116 ofstream out; 117 in.open("input.txt"); 118 out.open("output.txt"); 119 if(in.fail()) 120 cout<<"file did not open please check it\n"; 121 exit(0); 122 123 Student s[25]; 124 readData(in,s, 25); 125 assignGrades (5,25); 126 print (s, 25); 127 cout<<"\nThe Average is:"<<calculateAverage (5,25)<<endl; 128 cout<<"\nThe Variance is:"<<calculateVariance (s, 25) <<endl; 129 printHighest score (s, 25); 130 printLowest Score (s, 25); { ܝܟ

130 131 132 133 134 135 136 137 138 139 printLowest Score (s, 25); writeData (out,5,25); cout<<"Data is Saved into file named 'output.txt' Successfully..."<<endl; out.close(); in.close(); system("pause"); return 0; - }

2.OUTPUT:

0:1 C:\WINDOWS\system32\cmd.exe - a D:\cppsrc\FILES\StudentGrades>g++ StudentGrades.cpp D:\cppsrc\FILES\StudentGrades>a Student Name John, Smith Hank, Tom David, Hoper James, Michel John, Franklin Derrick, Myers Mary, Anna Margaret, Helen Elsie, Luky Dorothy, Mary Margaret, Ruth Annie, Elizabeth Helen, Mary Elsie, Agnes Lillian, Julia Mildred, Alice Elizabeth, Ruth Frances, Clara Emma, Anna Louise, Marie Peter, John Gorge, Peter Sallt, Bob Dorothy, Olga TestScore Grade 56 F 97 A 78 с 95 A 56 F 89 B 98 A 85 B 78 C 58 F 77 C 45 F 75 C 35 F 48 F 65 D 68 D 39 F 86 B 95 A 84 B 69 D 86 B 78 C

C.S. C:\WINDOWS\system32\cmd.exe-a Dorothy, Mary Margaret, Ruth Annie, Elizabeth Helen, Mary Elsie, Agnes Lillian, Julia Mildred, Alice Elizabeth, Ruth Frances, clara Emma, Anna Louise, Marie Peter, John Gorge, Peter Sallt, Bob Dorothy, Olga Rose, Sophie 58 77 45 75 35 48 65 68 39 86 95 84 69 86 78 79 F с F с F F D D F B A B D B с с The Average is:72.76 The Variance is:322 Highest Test Score: 98 Students having the highest test score: Mary, Anna Highest Test Score: 35 Students having the Lowest test score: Elsie, Agnes Data is Saved into file named 'output.txt' Successfully... Press any key to continue.

new 1 x StudentGrades.cpp X output.txt x 1 John, Smith 56 2 Hank, Tom 97 3 David, Hoper 78 4. James, Michel 95 5 John, Franklin 56 6 Derrick, Myers 89 7 Mary, Anna 98 8 Margaret, Helen 85 9 Elsie, Luky 78 10 Dorothy, Mary 58 11 Margaret, Ruth 77 12 Annie, Elizabeth 45 13 Helen, Mary 75 14 Elsie, Agnes 35 15 Lillian, Julia 48 16 Mildred, Alice 65 17 Elizabeth, Ruth 68 18 Frances, Clara 39 19 Emma, Anna 86 20 Louise, Marie 95 21 Peter, John 84 22 Gorge, Peter 69 23 Sallt, Bob 86 24 Dorothy, olga 78 25 Rose, Sophie 79 26

3.CODE:

#include <iostream> #include <string> #include <fstream> #include <iomanip> using namespace std; struct Student { string studentFName; string studentLName; int testScore; char grade; }; /*A function to read the students data (i.e. Names & test scores) from text file into an array*/ void readData(ifstream& in,Student s[],int size){    int n=0;    while(n<size){    in>>s[n].studentLName>>s[n].studentFName>>s[n].testScore;    n++; } } /* A function to write student data (i.e. Names, test scores, and grades) from the array to a text file.*/ void writeData(ofstream& out,Student s[],int size){    int n=0;    while(n<size){    out<<s[n].studentLName<<", "<<s[n].studentFName<<" "<<s[n].testScore<<endl;    n++; } } //A function to assign the relevant grade to each student. void assignGrades(Student s[], int size){    int i;    for(i=0;i<size;i++) if (s[i].testScore<60)        s[i].grade='F'; else if (s[i].testScore<70)        s[i].grade='D';    else if (s[i].testScore<80)        s[i].grade='C';    else if(s[i].testScore<90)        s[i].grade='B'; else        s[i].grade='A';    } /*A function to find the highest test score.*/ int findHighestScore(const Student s[], int size){    int high=0,i;    for(i=0;i<size;i++)    if (high < s[i].testScore )        high=s[i].testScore;    return high; } /*A function to find the lowest test score.*/ int findLowestScore(const Student s[], int size){    int low=100,i;    for(i=0;i<size;i++)    if (low > s[i].testScore )        low=s[i].testScore;    return low; } /*A function to find the average for all test scores.*/ double calculateAverage(const Student s[], int size){    double sum=0;    int i;    for(i=0;i<size;i++)        sum+=s[i].testScore;    return sum/size; } /*A function to find the variance of test scores*/ int calculateVariance(const Student s[], int size){    double sum=0,avg=0,v=0;    int i;    avg=calculateAverage(s,size);    for(i=0;i<size;i++){        v+=(s[i].testScore-avg)*(s[i].testScore-avg);    }    return v/size; } /*A function to print the names of student having the highest test score.*/ void printHighestScore(const Student s[], int size){    int high=0,i,hi=-1;    for(i=0;i<size;i++)    if (high < s[i].testScore ){        high=s[i].testScore;        hi=i;    }    cout<<"Highest Test Score: "<<high<<endl; cout<<"Students having the highest test score: "<<s[hi].studentLName<<", "<<s[hi].studentFName<<endl;    } /*A function to print the names of student having the lowest test score*/ void printLowestScore(const Student s[], int size){    int low=100,i,li=-1;    for(i=0;i<size;i++)    if (low > s[i].testScore ){        low=s[i].testScore;        li=i;    }    cout<<"Highest Test Score: "<<low<<endl; cout<<"Students having the Lowest test score: "<<s[li].studentLName<<", "<<s[li].studentFName<<endl;    } void print(const Student s[], int size){    cout<<left<<setw(30)<<"Student Name"<<right<<setw(20)<<"TestScore"<<right<<setw(7)<<"Grade"<<endl; string name; int high,i; for(i=0;i<size;i++) {    name=s[i].studentLName+", "+s[i].studentFName;    cout<<left<<setw(30)<<name<<right<<setw(20)<<s[i].testScore<<right<<setw(7)<<s[i].grade<<endl; } cout<<endl; } int main() { ifstream in;    ofstream out;    in.open("input.txt");    out.open("output.txt");    if(in.fail()) {        cout<<"file did not open please check it\n";        exit(0); } Student s[25]; readData(in,s,25); assignGrades(s,25); print(s,25);    cout<<"\nThe Average is:"<<calculateAverage(s,25)<<endl;    cout<<"\nThe Variance is:"<<calculateVariance(s,25)<<endl;    printHighestScore(s,25);    printLowestScore(s,25);    writeData(out,s,25);    cout<<"Data is Saved into file named 'output.txt' Successfully..."<<endl;    out.close(); in.close(); system("pause"); return 0; }

4.INPUT FILE:

input.txt:

John Smith 56 Hank Tom 97 David Hoper 78 James Michel 95 John Franklin 56 Derrick Myers 89 Mary Anna 98 Margaret Helen 85 Elsie Luky 78 Dorothy Mary 58 Margaret Ruth 77 Annie Elizabeth 45 Helen Mary 75 Elsie Agnes 35 Lillian Julia 48 Mildred Alice 65 Elizabeth Ruth 68 Frances Clara 39 Emma Anna 86 Louise Marie 95 Peter John 84 Gorge Peter 69 Sallt Bob 86 Dorothy Olga 78 Rose Sophie 79