Question

Hello I need a small fix in my program. I need to display the youngest student and the average age of all of the students. It is not working Thanks.

#include <iostream>

#include <iomanip>

#include <fstream>

#include <vector>

#include <algorithm>

using namespace std;

struct Student {

string firstName;

char middleName;

string lastName;

char collegeCode;

int locCode;

int seqCode;

int age;

};

struct sort_by_age {

inline bool operator() (const Student& s1, const Student& s2)

{

return (s1.age < s2.age); // sort according to age of student

}

};

// main function to run program

int main() {

//CHANGE: vector students; TO vector students;

vector<Student> students; // create vector object to hold students data

ifstream Myfile; // create input file stream object

Myfile.open("a2data.txt"); // open file

// check if file is open

if (!Myfile.is_open()) {

// display error message if file could not be opened

cout << "Could not open the file!";

return 0; //terminate

}

//CHANGE: vector words; TO vector words;

vector<string> words; // create vector object to store words from input file

//read input from file line by line

string line;

while (!Myfile.eof()) {

getline(Myfile, line); // readline from input file stream

line.c_str(); // convert string in to char array

// file given in eample does not contain one record each line

// but it hase some patern for reading

// each word is seprated by space

//read the liine till space is encountered and get the word

int i = 0; // iterator to iterate over line

string word = "";

while (line[i] != '\0') {

// loop till end of line

if (line[i] != ' ') {

word = word + line[i]; // build word with char

i++;

}

else {

if(word!="")

words.push_back(word); // add word to vector

word = ""; //reset word to empty string

i++; //ignore white space

}

}//end of line

words.push_back(word); // add word to vector

}//end of file

//when done reading input from file close the file stream

Myfile.close();

int count = 0; // counts the words proceesed from vector object words

string fname = words.at(count); // variable to store first name of student

count++; //move to next element in the vector

//CHANGE: count < words.size() TO count < words.size() - 2

// at least two words are read in an iteration, so at least two should remain to be read - last name + student id

while (count < words.size() - 2) {

// loop till end of vector words

// create student object

Student s;

//assign first name to student

s.firstName = fname;

//next element in words is middle name

//assign first char to middle name

string mname = words.at(count);

s.middleName = mname[0];

count++;

//next element is last name of student

//assign next word to student

s.lastName = words.at(count);

//CHANGE: start

//If there was no middle name, this is the student id + first name of next student

if(words.at(count).size() >= 12) // college code + locCode + seq + age

{

if(words.at(count)[1] >= '0' && words.at(count)[1] <= '9') // if second character is a digit

{

// this is the student id field, and there is no middle name

count --; // move one step back for next iteration

s.middleName = ' '; //blank middle name

s.lastName = words.at(count);

}

}

//CHANGE: end

count++;

//next element is student id + first name of next student

//id contains college code at first latter

string id = words.at(count);

count++;

//assign college code to the student

s.collegeCode = id[0];

//next 2 char in id contain location

string loc = "";

loc = loc + id[1];

loc = loc + id[2];

// assign location to student

s.locCode = stoi(loc); // convert string to integer

//next 6 char in id contain seqcode

string seq = "";

for (int j = 3; j < 9; j++) {

seq = seq + id[j];

}

// assign seqcode to student

s.seqCode = stoi(seq); //convert string to int

//next 3 char in id contains age

string age = "";

age = age + id[9];

age = age + id[10];

age = age + id[11];

//assign age to student

s.age = stoi(age); // convert string to int

//remainig latters in id contains next student's first name

// delete id of previous student to get name of next student

fname = id.erase(0, 12); // delete first 12 char from id and assign remaining to fname

// add student to student

students.push_back(s);

}

// clear the vector as done working with words

words.clear();

//sort vector according to age of students

sort(students.begin(), students.end(), sort_by_age());

// formating output

cout << setw(15) << left << "Last Name";

cout << setw(15) << left << "Midlle Name";

cout << setw(15) << left << "First Name";

cout << setw(15) << left << "College Code";

cout << setw(12) << left << "Location";

cout << setw(12) << left << "Sequence";

cout << setw(12) << left << "Age" << endl;

cout << "=======================================================================================" << endl;

// print all students

for (int i = 0; i < students.size(); i++) {

cout << setw(15) << left << students.at(i).lastName;

cout << setw(15) << left << students.at(i).middleName;

cout << setw(20) << left << students.at(i).firstName;

cout << setw(13) << left << students.at(i).collegeCode;

cout << setw(10) << left << students.at(i).locCode;

cout << setw(12) << left << students.at(i).seqCode;

cout << students.at(i).age << endl;

}

//print average age

cout << endl;

  

int avg_age = ageCalc(arry, youngest);

cout<<"Average age is: "<<avg_age<<endl;

cout<<"Youngest student is "<<youngest->firstName<<" "<<youngest->MiddleN<<" "<<youngest->LastN<<endl;

for(int i=0; i<index; i++){

delete arry[i];

}

return 0;

}

int ageCalc(Student *studs[], Student *&youngest){

youngest = studs[0];

int i = 0;

int avg_age = 0;

while(studs[i]!=NULL){

avg_age += studs[i]->age;

if(youngest->age>studs[i]->age)

youngest = studs[i];

i++;

}

return avg_age/i;

}

File needed:

https://drive.google.com/file/d/15_CxuGnFdnyIj6zhSC11oSgKEYrosHck/view?usp=sharing

Answer 1

//Mistakes and Modifications:
//Some syntax errors in your code like using LastN data field of Student class which is not present in it.
//you can clear the Student objects in vector by using students.clear() method of vector.
//you don't have to iterate through each vector element.
#include <iostream>
#include <iomanip>
#include <fstream>
#include <vector>
#include <algorithm>
using namespace std;
struct Student
{
string firstName;
char middleName;
string lastName;
char collegeCode;
int locCode;
int seqCode;
int age;
};
struct sort_by_age
{
inline bool operator() (const Student& s1, const Student& s2)
{
return (s1.age < s2.age); // sort according to age of student
}
};
//declare the ageCalc() method since it is implemented on bottom of the code.
//you can use vector<Student> instead of pointers of Student array.
//you can't convert the vector<Student> into *Student[] studs type.
//and you can pass the Student object youngest using reference of that object.
//reference internally considers the address no need to create Student *&youngest.
//Student &youngest will be enough.
int ageCalc(vector<Student>studs, Student &youngest);

// main function to run program
int main()
{
//CHANGE: vector students; TO vector students;
vector<Student> students; // create vector object to hold students data
ifstream Myfile; // create input file stream object
  
Myfile.open("a2data.txt"); // open file
  
// check if file is open
if (!Myfile.is_open())
{
// display error message if file could not be opened
cout << "Could not open the file!";
return 0; //terminate
}
//CHANGE: vector words; TO vector words;
vector<string> words; // create vector object to store words from input file
//read input from file line by line
string line;
while (!Myfile.eof())
{
getline(Myfile, line); // readline from input file stream
line.c_str(); // convert string in to char array
// file given in eample does not contain one record each line
// but it hase some patern for reading
// each word is seprated by space
//read the liine till space is encountered and get the word
int i = 0; // iterator to iterate over line
string word = "";
while (line[i] != '\0')
{
// loop till end of line
if (line[i] != ' ')
{
word = word + line[i]; // build word with char
i++;
}
else
{
if(word!="")
words.push_back(word); // add word to vector
word = ""; //reset word to empty string
i++; //ignore white space
}
}//end of line
words.push_back(word); // add word to vector
}//end of file
  
//when done reading input from file close the file stream
Myfile.close();
int count = 0; // counts the words proceesed from vector object words
string fname = words.at(count); // variable to store first name of student
count++; //move to next element in the vector
//CHANGE: count < words.size() TO count < words.size() - 2
// at least two words are read in an iteration, so at least two should remain to be read - last name + student id
while (count < words.size() - 2)
{
// loop till end of vector words
// create student object
Student s;
//assign first name to student
s.firstName = fname;
//next element in words is middle name
//assign first char to middle name
string mname = words.at(count);
s.middleName = mname[0];
count++;
//next element is last name of student
//assign next word to student
s.lastName = words.at(count);
//CHANGE: start
//If there was no middle name, this is the student id + first name of next student
if(words.at(count).size() >= 12) // college code + locCode + seq + age
{
if(words.at(count)[1] >= '0' && words.at(count)[1] <= '9') // if second character is a digit
{
// this is the student id field, and there is no middle name
count --; // move one step back for next iteration
s.middleName = ' '; //blank middle name
s.lastName = words.at(count);
}
}
//CHANGE: end
count++;
//next element is student id + first name of next student
//id contains college code at first latter
string id = words.at(count);
count++;
//assign college code to the student
s.collegeCode = id[0];
//next 2 char in id contain location
string loc = "";
loc = loc + id[1];
loc = loc + id[2];
// assign location to student
s.locCode = stoi(loc); // convert string to integer
//next 6 char in id contain seqcode
string seq = "";
for (int j = 3; j < 9; j++)
{
seq = seq + id[j];
}
// assign seqcode to student
s.seqCode = stoi(seq); //convert string to int
//next 3 char in id contains age
string age = "";
age = age + id[9];
age = age + id[10];
age = age + id[11];
//assign age to student
s.age = stoi(age); // convert string to int
//remainig latters in id contains next student's first name
// delete id of previous student to get name of next student
fname = id.erase(0, 12); // delete first 12 char from id and assign remaining to fname
// add student to student
students.push_back(s);
}
// clear the vector as done working with words
words.clear();
//sort vector according to age of students
sort(students.begin(), students.end(), sort_by_age());
// formating output
cout << setw(15) << left << "Last Name";
cout << setw(15) << left << "Midlle Name";
cout << setw(15) << left << "First Name";
cout << setw(15) << left << "College Code";
cout << setw(12) << left << "Location";
cout << setw(12) << left << "Sequence";
cout << setw(12) << left << "Age" << endl;
cout << "=======================================================================================" << endl;
// print all students
for (int i = 0; i < students.size(); i++)
{
cout << setw(15) << left << students.at(i).lastName;
cout << setw(15) << left << students.at(i).middleName;
cout << setw(20) << left << students.at(i).firstName;
cout << setw(13) << left << students.at(i).collegeCode;
cout << setw(10) << left << students.at(i).locCode;
cout << setw(12) << left << students.at(i).seqCode;
cout << students.at(i).age << endl;
}
  
//print average age
cout << endl;
//youngest Student object is not created in the code posted in question.
//you can pass the vector of Student objects
Student youngest;
int avg_age = ageCalc(students, youngest);
//since we have used Student object we have to print youngest object fields
//using . not -> .
cout<<"Average age is: "<<avg_age<<endl;
cout<<"Youngest student is "<<youngest.firstName<<" "<<youngest.middleName<<" "<<youngest.lastName<<endl;
int index = students.size();
//you can clear the Student objects in vector by using students.clear() method of vector.
students.clear();
return 0;
}
//method definiton.
//takes an vector of Student object and Student object reference to store the
//youngest Student.
int ageCalc(vector<Student> studs, Student &youngest)
{
//assume the first student as younges
youngest = studs[0];
int i = 0;
//average age.
int avg_age = 0;
//here vector class has method size()that returns the number of elemnets
//in vector.
int size =studs.size();
//till the index i less than size.
while(i<size)
{
//add i_th student age to avg_age.
//since we are uusing vector of Student objects
//we access object fields using . not with ->
avg_age += studs[i].age;
//since we have used Student object not pointer of Studnet object.
//we access fields using . not with ->
if(youngest.age>studs[i].age)
//modify the younges Studnet if the current youngest one age > current student.
youngest = studs[i];
//goto next student.
i++;
}
//return average.
//here you can use i or size variable both haves the
//count of total objects in passed vector.
return avg_age/i;
}
//FINAL OUTPUT --------------------

//PLEASE LIKE THE ANSWER AND COMMENT IF YOU WANT ANY MODIFICATIONS.