Thread: help woth cout 3d string array

Hi All
im new to c++
i got an assignment to make a grade sheet. using 3d arrays
but now i am having problem with displaying result.
when only 1 subject it works fine but it doesn't work for 2 or more subjects
need help fast.
here's my attempt

Code:

#include <iostream>
#include <string>
#include <sstream>
using namespace std;
float str2flt(string str)		
{
	float i;
	stringstream iss(str);		
	iss >> i;					
	return i;
}
string flt2str(float no)		
{
	stringstream iss;			
	iss << no;					
	return iss.str();			 
}

/* Making an 3d array of string type all the input paramters are given by user (no of grade sheets, Students, and no. of evaluations) */
void main ()
{
	string ***array={0};		 
	int *data={0};				// for remembering individual input for no. of students of diffrent subjects
	float j,u,n,i,ax,a=0;
	int sub,std,ppr;
	cout<<"Enter No. Of Subjects : ";
	cin>>sub;
	data=new int [sub];
	for(int su=0;su<sub;su++)
	{
		array=new string **[sub]; //x
		cout<<"Enter No. Of Students for subject no. "<<su+1<<" : ";
		cin>>std;
		data[su]=std;
		array[su]=new string *[std+1];				//y   +1 because of in 0 0 0 name of subject will be stored
		cout<<"Enter No. Of Evaluations for subject no. "<<su+1<<" : ";
		cin>>ppr;
		for(int p=0;p<=std;p++)
		{
			array[su][p]=new string [ppr+3];		/* z   +3 cuz on location [o][o][n] name of students will be stored,
													on [x][y][ppr+1] avrg will b stored and on [x][y][ppr+2] grade will be stored */
		}
		// declartion completed
		cout<<"Enter Name Of The Subject no. "<<su+1<<" (no Spaces) : ";
		cin>>array[su][0][0];
		cout<<"Please Input Evaluation Weightages for Subject "<<array[su][0][0]<<" (ex:0.3 for 30%)\n";
		for(int w=1;w<=ppr;w++)
		{
			do{ 
			cout<<"Enter Weightage for evaluation no. "<<w<<" : ";
			cin>>array[su][0][w];
			}while(str2flt(array[su][0][w]) > 1 || str2flt(array[su][0][w]) <0); 
		}
		for(int s=1;s<=std;s++)
		{
			cout<<"Enter Name of Student no. "<<s<<" For Subject of "<<array[su][0][0]<<" (0-100): ";
			cin>>array[su][s][0];
			for(int no=1;no<=ppr;no++)
			{
				do{
				cout<<"Enter Score of "<<array[su][s][0]<<" for evaluation no "<<no<<" : ";
				cin>>array[su][s][no];
				}while(str2flt(array[su][s][no]) >100 || str2flt(array[su][s][no]) <0);
			}
		}
		//data input complete
		for(int x=1;x<=ppr;x++) // on z
		{
			a+=str2flt(array[su][0][x]);
		}
		array[su][0][ppr+1]=flt2str(a);// w(normalizer) calculated and stored on [0][0][ppr+1]
		
		for(int avg=1;avg<=std;avg++) // on y
		{
			a=0;
			for(int sn=1;sn<=ppr;sn++) // on z
			{
				j=str2flt(array[su][avg][sn]);
				u=str2flt(array[su][0][sn]);
				n=j*u;
				i=str2flt(array[su][0][ppr+1]);
				ax=n /i;
				a+=ax;
			}
			array[su][avg][ppr+1]=flt2str(a);
		}
		//average calculate wid proper weights and normalized
		for(int g=1;g<=std;g++)
		{
			int chk;
			chk=str2flt(array[su][g][ppr+1]);
			if(chk < 60)
				array[su][g][ppr+2]='F';
			else if(chk <70)
				array[su][g][ppr+2]='D';
			else if(chk<80)
				array[su][g][ppr+2]='C';
			else if(chk<90)
				array[su][g][ppr+2]='B';
			else
				array[su][g][ppr+2]='A';
		}
			
		} 
	/* OutPut Code */
		for(int t=0;t<sub;t++)
		{
			cout<<array[t][0][0]<<"\n";
			int ou=1;
			while(ou<=data[t])
				{
					cout<<array[t][ou][0]<<"\t";
					cout<<array[t][ou][ppr+1]<<"\t";
					cout<<array[t][ou][ppr+2]<<endl;
					ou++;
				}
		}
	cout<<"\n\n>------------------------------------------------------------------------------<";

}//main end

Any one ?

Triple indirection is nasty. Do you have to use a 3D array? Can you use any other data structure to simplify this? A 3D array is almost never the correct approach.

Thanks brother
and sry am new to all this o
thanks again

Originally Posted by Salem

I see (barely in the poor indentation) two big problems

> array=new string **[sub]; //x
You're reallocating your main array EVERY time around the loop. Do this outside the loop, not inside.

I also see a lot of
for(int g=1;g<=std;g++)

subscripting begins at 0, not 1
This usually means you're stepping off the ends of any array you only allocated 'std' elements to.


Not to mention the whole void main thing.