Shami's work

#include<iostream>
#include<fstream>
#include<sstream>
#include<algorithm>
#include<string>
#include<vector>
#include<map>
#include<numeric>

using namespace std;
typedef struct STUDENT_DATA {
    int id;
    string name;
    int marks[3];
}StudentData, *PStudentData;

void read(std::vector<StudentData> *pData)
{
    ifstream fin;
    stringstream temp;
    StudentData tmp;
    string id, name, mark;
    fin.open("course.csv");
    string line;
    int i=0;
    while(getline(fin, line))
    {
        stringstream ss(line);
        getline(ss, id, ',');
        getline(ss, name, ',');
        for(int j=0;j<3;j++){
            getline(ss, mark, ',');
            tmp.marks[j] = atoi(mark.c_str());
        }
        tmp.id = atoi(id.c_str());
        tmp.name = name;
        pData->push_back(tmp);
        i++;

    }
    fin.close();
}

void print(StudentData data){
    std::cout<<std::endl;
    std::cout   << "\nid: "<< data.id
                << "\nname: "<< data.name
                << "\nmarks:";
    for(int j=0;j<3;j++)
        std::cout << data.marks[j] << ((j<2)?", ":"");
}

void printAll(std::vector<StudentData> *pData){
    for(auto data:(*pData))
        print(data);
}

void sum(std::vector<StudentData> *pData)
{
    int num;
    cout << "enter id: ";
    cin >> num;
    for (auto i:(*pData)){
        if (i.id == num) {
            std::cout   << "name: "<< i.name
                        << "\navg: "<< (float)std::accumulate(i.marks,i.marks + 3, 0) / 3;
        }
    }
}

void avg(std::vector<StudentData> *pData)
{
    int exam;
    float sum = 0;
    cout << "enter exam no.: ";
    cin >> exam;
    for (auto i:(*pData)){
        sum += i.marks[exam-1];
    }
    std::cout << "avg in exam " <<exam<< ": "<< sum / (float)(pData->size());
}

void avgTotal(std::vector<StudentData> *pData)
{
    float sum = 0;
    for (auto i:(*pData)){
        sum += std::accumulate(i.marks,i.marks + 3, 0);
    }
    std::cout << "overall avg: " << sum / (float)(pData->size());
}

void update(std::vector<StudentData> *pData){
    int id,tmp;
    char* tmpName;
    std::cout<<"enter id: ";std::cin>>id;
    for(int i=0;i<pData->size();i++){
        if((*pData)[i].id == id){
            //cout<<(*pData)[i].name;getch();
            std::cout<<"enter new details:-\n";
            std::cout<<"name: ";cin>>tmpName;
            (*pData)[i].name = tmpName;
            for(int j=0;j<3;j++){
                std::cout<<"marks in subject "<<j+1<<": ";cin>>(*pData)[i].marks[j];
            }
            break;

        }
    }
}

void store(std::vector<StudentData> *pData)
{
    ofstream fout;
    //StudentData temp;
    string tmp;
    fout.open("tmp.csv",ios::trunc);
    if(fout.is_open()){
        for(auto i:(*pData)){
            tmp = std::to_string(i.id) + "," + i.name;
            for(int j=0;j<3;j++)
                tmp+= ("," + std::to_string(i.marks[j]));
            fout<<tmp<<'\n';
        }
        fout.close();
        std::cout<<"\nData saved!";
    }
    else{
        std::cout<<"\nerror: file cannot be created";
    }
}

void reload(std::vector<StudentData> *pData){
    read(pData);
}

void displaySortedAvg(std::vector<StudentData> *pData){
    int tmp;
    std::vector<int> sortedSubscript;
    for(int i=0;i<pData->size();i++)
        sortedSubscript.push_back(i);
    float highest = -1,avg1,avg2;
    for(int i=0;i<pData->size();i++){
        avg1 = (float)std::accumulate((*pData)[i].marks,(*pData)[i].marks + 3, 0) / 3;
        cout<< avg1 << ' ';
        for(int j=1;j<pData->size();j++){
            avg2 = (float)std::accumulate((*pData)[j].marks,(*pData)[j].marks + 3, 0) / 3;
            if(avg1 < avg2)
                highest = j;
            else
                highest = i;
        }
        tmp = sortedSubscript[i];
        sortedSubscript[i] = sortedSubscript[highest];
        sortedSubscript[highest] = tmp;
    }
    for(auto i:sortedSubscript)
        print((*pData)[i]);
}

 void histogram(std::vector<StudentData> *pData){
     std::map<int,int> sortedGraphData;
     std::vector<int> x_axisPoints,y_axisValues;
     int tmp,k, maxMarks = -1;

     for(auto i:(*pData)){
        for(int j=0;j<3;j++){
            sortedGraphData[i.marks[j]] += 1;
        }
     }
     for(auto x:sortedGraphData)
        if(x.first > maxMarks)
            maxMarks = x.first;
     maxMarks = maxMarks - maxMarks%10 + 10;
     for(int j=10;j<=maxMarks;j+=10){
        tmp = 0;
        for(auto x:sortedGraphData){
        if(x.first <= j && x.first > j-10){
            tmp += x.second;
            }
        }
        if(tmp){
            x_axisPoints.push_back(tmp);
        }
    }

    y_axisValues = x_axisPoints;
    std::sort(y_axisValues.begin(),y_axisValues.end(),[](int x,int y)->bool{return (x>y);});
    y_axisValues.push_back(0);

    k=0;
    for(auto i:y_axisValues){
       std::cout<< i << ((i<10)?"  ":" ") << char(179) << char(179);
       for(int j=10;j<=x_axisPoints.size()*10;j+=10){
            cout<<"  "<<((x_axisPoints[(j/10) - 1] >= i)? (char)177:(char)32);

       }
       std::cout<<std::endl;
     }
     for(int i=0;i<x_axisPoints.size()*3 + 6;i++)
        cout<<((i == 3 || i == 4)? (char)216: (char)205);
     cout<<endl<<"   "<<(char)179<<(char)179<<"  ";
     for(int j=10;j<=x_axisPoints.size()*10;j+=10)
        cout<<j<<' ';
 }

int main()
{
        std::vector<StudentData> data;
        std::vector<StudentData> *pData = &data;
        int num;
        std::string homeText[] = {  "1. print the content of the file on screen",
                                    "2. print the total grade of a student in an exam",
                                    "3. Print the average grade in a certain exam",
                                    "4. Print the average of total grade for all students",
                                    "5. Update student information",
                                    "6. Store the updated content of the array into the file",
                                    "7. Reload the content of the file",
                                    "8. display records according to the total grade in descending order",
                                    "9. draw a histogram for total grades",
                                    "10. Exit"
        };
        void (*lookUpTable[])(std::vector<StudentData>*) = {
            printAll,
            sum,
            avg,
            avgTotal,
            update,
            store,
            reload,
            displaySortedAvg,
            histogram
        };
        for(auto str:homeText){
            cout<<str<<endl;
        }
        read(pData);
        do {
            cout << "\n\nchoose option:";
            cin >> num;
            if(num <= 10 && num > 0){
                cout << endl << (homeText[num-1].c_str() + 3) << endl << endl;
                lookUpTable[num-1](pData);
            }
        } while (num != 10);
    return 0;
}