/*

Write a program that reads in a data file of student

first names, last names and quiz scores. Print out

the students from highest grade to lowest, where

within a group with the same quiz grade, students are

printed out alphabetically by last name.

*/

#include <iostream>

#include <fstream>

#include <string>

using namespace std;

/****** STRUCTS AND PROTOTYPES *********************/

struct Student

{

string first, last;

int grade;

};

istream& operator>>(istream& in, Student &S);

ostream& operator<<(ostream& out, Student S);

void sort(Student *A, int N);

void swap(Student &studentA, Student &studentB);

// a comes before b if a has the higher grade.

// Ties are broken by alphabetical order of last name.

// Further ties broken by alphabetical order of first name

bool before(Student a, Student b);

/****** MAIN ***************************************/

int main()

{

// Get file name and open file

string fname;

cout << "Enter file name: ";

cin >> fname;

ifstream fin(fname.c_str());

// Allocate array of students and read data from file

int n;

string junk;

fin >> n >> junk;

Student *S = new Student[n];

for(int i = 0; i < n && fin >> S[i]; ++i);

// Sort array and print out array contents

sort(S,n);

for(i = 0; i < n; ++i)

cout << S[i] << endl;

return 0;

}

/****** FUNCTION DEFINITIONS ***********************/

istream& operator>>(istream& in, Student &S)

{

return in >> S.first >> S.last >> S.grade;

}

ostream& operator<<(ostream& out, Student S)

{

return out << S.first << ' ' << S.last << ' ' << S.grade;

}

bool before(Student a, Student b)

{

if(a.grade==b.grade)

if (a.last<b.last)

return true;

else

return false;

else

if (a.grade<b.grade)

return false;

else

return true;

}

void sort(Student *A, int N)

{

for(int length = N; length > 1; length--)

{

// Find imax, the index of the largest

int imax = 0, i;

for(i = 1; i < length; i++)

if (before(A[imax],A[i]))

imax = i;

swap(A[imax],A[length-1]);

}

}

void swap(Student &studentA, Student &studentB)

{

Student temp = studentA;

studentA = studentB;

studentB = temp;

}