How to change this data sturucture from vector <int> total; to float total;? because if I change it to float teher is many error....

#include <iostream>   // std::cout
#include <fstream>
#include <iomanip>
#include <string>    // std::string
#include <vector>    // std::vector<>
#include <algorithm> //std::for each()
using namespace std; // import "std" namespace into global namespace

struct exam
{
int examid;
vector <int> total;
};

void SwapMembers (int items[], int index1, int index2)
{
	int temp;
	temp=items[index1];
	items[index1]=items[index2];
	items[index2]=temp;
}

	int main() 
	{
	ifstream stream1("STA83SOLUTION.txt");
		if ( !stream1.is_open())
		{
		cout << "While opening a file an error is encountered" << endl;
		} 
			else 
			{
			cout << "Fail Di buka....." << endl;
			}
	vector <exam> exams;
	exam aExam;
   int tempExamID;
    int tempTotal;
    stream1 >> tempExamID >> tempTotal;
    aExam.examid = tempExamID;
    aExam.total.push_back(tempTotal); // add this exam code to current student's vector of exam codes
    while (stream1 >> tempExamID >> tempTotal)
    {
        if(tempExamID != aExam.examid)
        {
        exams.push_back(aExam); // no more exam codes for this student.  Add aStudent to students vector
        aExam.total.clear();
        aExam.examid = tempExamID;
        }
        aExam.total.push_back(tempTotal); // add this exam code to current student's vector of exam codes
    }
    exams.push_back(aExam); // no more exam codes for this student.  Add aStudent to students vector
    stream1.close(); // We have read the entire file, so time to close it.
{
	ofstream myfile;
	myfile.open("411.txt");
	
	int temp, flag;
	if (myfile.is_open())
	{
		for (size_t i = 0; i < exams.size(); i++) 
		{
			for (size_t j = 0; j<exams.at(i).total.size(); j++) 
			{
				if (exams.at(i).total.size() < exams.at(i).total.size()+1)      // ascending order simply changes to <
				{ 
                    temp = exams.at(i).total.size();             // swap elements
                    exams.at(i).total.size() = exams.at(i).total.size()+1;
                    exams.at(i).total.size()+1 = temp;
                    flag = 1;               // indicates that a swap occurred.
                }

		cout<<"\n"<<i+1<<":"<<" "<< exams.at (i).total.at(j)<<"\t"; // output list of exam codes for this student
	  	cout<<" "<< exams.at (i).total.at(j)<<"\t";
			}
		}
	}
					
cin.get();
return 0;
}
}

you mean you want the structure to look like this:

struct exam
{
int examid;
float total;
};

You will have to make a lot of code changes to do that because total is no long an array of ints. I suppose instead of push_back(123) just add 123 to the current value of total.

yes...I want to do like that but

" instead of push_back(123) just add 123 to the current value of total. "

123 ?I dont understand...Ancient Dragon.

>>123 ?I dont understand...Ancient Dragon.

That was just a generic thing to mean any number -- whatever number you used in the push_back() function call.

initialize it to 0 when you create the array of structures. Something like this

struct exam array[20];
for(int i = 0; i < 20; i++)
   array.total = 0;

I have done like this.. but still many error..
i have change ti float..then for array.total i change to size.total=0.

rror C2228: left of '.push_back' must have class/struct/union type
F:\460.cpp(37) : error C2228: left of '.clear' must have class/struct/union type
F:\460.cpp(40) : error C2228: left of '.push_back' must have class/struct/union type
F:\460.cpp(53) : error C2228: left of '.size' must have class/struct/union type
F:\460.cpp(56) : error C2228: left of '.total' must have class/struct/union type
F:\460.cpp(57) : error C2228: left of '.at' must have class/struct/union type
Error executing cl.exe.

#include <iostream>   // std::cout
#include <fstream>
#include <iomanip>
#include <string>    // std::string
#include <vector>    // std::vector<>
#include <algorithm> //std::for each()
using namespace std; // import "std" namespace into global namespace

struct exam
{
int examid;
float total;
};
	int main() 
	{
	ifstream stream1("STA83SOLUTION.txt");
		if ( !stream1.is_open())
		{
		cout << "While opening a file an error is encountered" << endl;
		} 
			else 
			{
			cout << "Fail Di buka....." << endl;
			}
	vector <exam> exams;
	exam aExam;
    int tempExamID;
    int tempTotal;
    stream1 >> tempExamID >> tempTotal;
    aExam.examid = tempExamID;
    aExam.total.push_back(tempTotal); // add this exam code to current student's vector of exam codes
    while (stream1 >> tempExamID >> tempTotal)
    {
        if(tempExamID != aExam.examid)
        {
        exams.push_back(aExam); // no more exam codes for this student.  Add aStudent to students vector
        aExam.total.clear();
        aExam.examid = tempExamID;
        }
        aExam.total.push_back(tempTotal); // add this exam code to current student's vector of exam codes
    }
    exams.push_back(aExam); // no more exam codes for this student.  Add aStudent to students vector
    stream1.close(); // We have read the entire file, so time to close it.
{
	ofstream myfile;
	myfile.open("411.txt");
	
	int temp, flag;
	if (myfile.is_open())
	{
		for (size_t i = 0; i < exams.size(); i++) 
		{
			for (size_t j = 0; j<exams.at(i).total.size(); j++) 
			{

	size.total = 0;
		cout<<"\n"<<i+1<<":"<<" "<< exams.at (i).total.at(j)<<"\t"; // output list of exam codes for this student
	  		}
		}
	}
					
cin.get();
return 0;
}
}

>>I have done like this.. but still many error..
So, fix the errors. After all this time you should know how to recognize the errors and correct them.

Why you want to change vector<int> to float? Do you want to use the float total to store the sum of the exam codes? maybe you can add a member to your struct. like this:

struct exam
{
  int examid;
  vector <int> examcodelist;
  float total;
};

In addition, in you source code, you use at() to access vector, but you don't catch the range error exception. so, it make no sense. for performance consider, you'd better use '[]' instead of 'at() '.

This article has been dead for over six months. Start a new discussion instead.