test

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>

/* type definition of student */
typedef struct student {
  int who;     /* 0=John, 1=Peter, 2=William */
  float paid;  /* amount that student paid   */
} student;

/* global variables */
student firstStudent, secondStudent, thirdStudent;
float totalPaid;
/************************************************************************
 * ABSTRACT DATA TYPE: the following functions form the ADT student.
 * Do not change the ADT part of this program !
 */

/* read the info of a student from the keyboard and return it. */
void readStudent(student *stud) {
  scanf("%d %f", &stud->who, &stud->paid);
}

/* print the name of a student. */
void printNameOfStudent(student stud) {
  printf("%s", (stud.who == 0 ? "John" : (stud.who == 1 ? "Peter" : "William")));
}

/* returns the amount that a student paid. */
float paidByStudent(student stud) {
  return stud.paid;
}

/* swaps two students */
void swapStudents(student *a, student *b) {
  student h = *a;
  *a = *b;
  *b = h;
}

void orderStudents(){
  /* Order the students by the amount of money
     they need to pay or receive. */
  if(paidByStudent(firstStudent) > paidByStudent(secondStudent)) swapStudents(&firstStudent, &secondStudent);
  if(paidByStudent(secondStudent) > paidByStudent(thirdStudent)) swapStudents(&secondStudent, &thirdStudent);
  if(paidByStudent(firstStudent) > paidByStudent(secondStudent)) swapStudents(&firstStudent, &secondStudent);
}

float absoluteFloat(float k)
{
  return (k < 0) ? (k * -1) : (k);
}

void printResult(student *stud)
{
  printNameOfStudent(*stud);
  /* If price to pay is lower or equal to zero student will receveive money
  Converts price to pay to an absolute value */

  printf(" %s %3.2f\n",((totalPaid / 3 - stud->paid > 0) ? ("pays") : ("receives")),absoluteFloat(totalPaid / 3 - stud->paid));
}


void readInput() {
  readStudent(&firstStudent);
  readStudent(&secondStudent);
  readStudent(&thirdStudent);
}


int main(int argc, char *argv[]) {
  readInput();

  /*Total of amound spent by student */
  totalPaid = paidByStudent(firstStudent) + paidByStudent(secondStudent) + paidByStudent(thirdStudent);

  /*Place students in the correct order */
  orderStudents();

  /*Print Result */
  printResult(&firstStudent);
  printResult(&secondStudent);
  printResult(&thirdStudent);

  return 0;
}