segmentation fault

[print]

hi all.. i was stuck at this problem for quite some time. i do not know if my program will produce a correct output or not, because i got segmentation fault.. and i have been struggling to figure it out. i try debugging the program, and it says I have the problem at compute average. but I do not know how to fix it.

#include <iostream>
#include <cmath>
#include <iomanip>

using namespace std;

// FUNCTION PROTOTYPES GO HERE:
   void read_student(int & students);	
   void read_exams(int students,int * scores1, int * scores2, int * scores3);
   void compute_totals(int students,int*scores1,int * scores2, int* scores3,int* totals);
   double compute_average(int students,int *totals);
   int find_min(int students, int * totals); 
   int find_max(int students, int * totals);
   int above_average(int * totals,int students,double avg);
   void display_table(int *scores1, int *scores2, int *scores3,int *totals,int students, double avg,int max,int min,int above);
   void print_top();
   void call_student(int students,int *scores1,int *scores2,int *scores3,int *totals,double avg);
   void print_bottom(int students,double avg,int min,int max,int above);

int main()
{
	int * scores1;
	int * scores2;
	int * scores3;
	int * totals;
	int students(0);
	double avg(0.0);
	int min, max, above;
	

	// Prompt for the number of students
	   read_student(students);

	// Allocate arrays to hold exam scores and totals
	   scores1 = new int[students];
	   scores2 = new int[students];
	   scores3 = new int[students];
	   totals = new int[students];

	// Prompt and read exams for each student
	   read_exams(students,scores1,scores2,scores3);

	// Compute exam totals for each student
	   compute_totals(students,scores1,scores2,scores3,totals);

	// Compute the average of the total scores
           avg = compute_average(students,totals);

	// Find the minimum total score
	   min =find_min(students,totals);

	// Find the maximum total score
	   max = find_max(students,totals);

	// Compute the number of students with total scores at or average of the total scores
	   above = above_average(totals,students,avg);
	   
	// Display table
	   display_table(scores1,scores2,scores3,totals,students,avg,max,min,above);
	   
	// De-allocate arrays
	   delete [] scores1;
	   delete [] scores2;
	   delete [] scores3;
	   delete [] totals;


	return 0;
}
		 
	// FUNCTION DEFINITIONS GO HERE:
	void read_student(int & students )
	   {
		cout<<"Enter number of student: "; //ask user input
			
		while (cin>>students && students<=0) //check if user input is >0
		{
			cout<<"Sorry, you must enter positive value."<<endl;
			cout<<"Enter number of student: ";	
		}
		cout<<endl;
	   }
	
	void read_exams(int students,int * scores1, int * scores2, int * scores3)
	   {
		
		for(int i=0; i<students;i++)
		{
			cout<<"Enter the three exam scores for student #"<<i+1<<":";
		        cin>>scores1[i]>>scores2[i]>>scores3[i];	

		}
	   } 
	 void compute_totals(int students,int*scores1,int * scores2, int* scores3,int* totals)
	{
		for(int i =0;i<students; i++)
		{
			totals[i] = scores1[i] + scores2 [i] + scores3 [i];
		}
	}

	 double compute_average(int students,int *totals)
	{
		double average(0.0);		
		int total(0);
	
		for (int i=0; i<students; i++)
		{
			total +=totals[i];
		}
		
		average = double(total)/students;

		return(average);	
	}
	 int find_min(int students, int * totals)
	{
		int min= totals[0];

		for (int i=1;i<students;i++)
		{
			if(totals[i] < totals[0])
			{
				min=totals[i];
			} 
		}	
		return (min);
	}
	 int find_max(int students, int * totals)
	{
		int max= totals[0];

		for (int i=1;i<students;i++)
		{
			if(totals[i] > totals[0])
			{
				max=totals[i];
			} 
		}	
		return (max);
	}
	
	int above_average(int * totals,int students,double avg)
	{
		int up(0);

		for (int i=0;i<students;i++)
		{
			if(totals[i]>avg)
			{
				up++;
			}
		}
		return (up);
	}
	
	void display_table(int *scores1, int *scores2, int *scores3,int *totals,int students, double avg,int max,int min,int above)
	{
	
		//call function 1
		print_top;
		//call function 2
		for(int i=0;i<=students;i++)
		{	
			call_student(students, scores1,scores2,scores3,totals,avg);	
		}	
		//call function 3
		print_bottom(students,avg,min,max,above);
	
	}

	//function 1
	void print_top()
	{
		cout<<"-----------------------------------------------"<<endl;
		cout<<"Student"<<setw(3)<<"Score 1"<<setw(3)<<"Score 2"<<setw(3)<<"Score 3"<<setw(3)<<"total";
	}

	//function 2
	void call_student(int students,int *scores1,int *scores2,int *scores3,int *totals,double avg)
	{
		int i;		
		
		cout<<i+1<<setw(3)<<scores1<<setw(3)<<scores2<<setw(3)<<scores3<<setw(3)<<totals;
		
		if(totals[i]>avg)
		{
			cout<<"+"<<endl;
		}else if(totals[i]<avg)
		{
			cout<<"-"<<endl;
		}else
		cout<<"="<<endl;	
	}
	
	//function 3
	void print_bottom(int students,double avg,int min,int max,int above)
	{
		cout<<"-----------------------------------------------"<<endl;
		cout<<"-----------------------------------------------"<<endl;
		cout<<"The number of Students is:"<<students;
		avg = round(avg);
		cout<<"The avg total score (rounded) is:"<<avg;
		cout<<"The maximum total score is:"<<max;
		cout<<"The minimum total score is:"<<min;
		cout<<"Total scores at or above the avg is:"<<above;
		cout<<"-----------------------------------------------"<<endl;	
	}

example of the correct out put right here

Enter number of students: 3

Enter the three exam scores for student #1: 11 12 13
Enter the three exam scores for student #2: 11 14 15
Enter the three exam scores for student #3: 16 17 18

-----------------------------------------------
Student   Score 1   Score 2   Score 3   Total
-----------------------------------------------
      1   11        12        13        36    -
      2   11        14        15        40    -
      3   16        17        18        51    +
-----------------------------------------------
The number of students is:              3
The avg total score (rounded) is:       42
The maximum total score is:             51
The minimum total score is:             36
Total scores at or above the avg is:    1
-----------------------------------------------

[helios]

for (int i=0; i, students; i++)

Not sure what you meant here, but the condition should be i < students.

Explanation: the comma operator evaluates each expression successively and has the value of the last expression. So, for instance, x = (54 == 42), 13; will assign 13 to x. Of course, all the expressions that are not the last one and don't have side effects do nothing. That example is equivalent to just x = 13;, but not to x = i++, 13;.

[print]

yea, my error there, I just fixed it..
after i change it into "i<students",

the segmentation fault still shows up.


I am not sure what should do to fix this problem..

[helios]

There's another one in the loop condition in display_table(). <= instead of <.

[print]

i will try to fix that, but i think the main problem is the compute_average. because my program stuck there and cannot produce the remaining input.


so, unless i could figure out what to do in there, any change that I do below the compute average is kinda useless..

because i cannot check it, and i still could compile the program

[helios]

Well, compute_average() is correct, so the problem is definitely not there. Besides find_max() and find_min() which are incorrect, and call_student() which prints pointers instead of data, I can't find any other obvious bugs. Certainly nothing that would cause a crash.
Are you sure you didn't forget to recompile?

[print]

i find the problem when i ask my friend, now i am trying to finish it. thanks for the help, appreciate it.