C ++读入二维数组问题

Question

this is the first time I'm using stock overflow. I'm using visual studio 2012 which uses C++, so the code's a bit odd, my apologies. I can really use some help; I'm starting to get really anxious and everything I'm doing now is ending up in errors.

I've got to write a program that has to print out a 2d array using a text file, find the average and the total sum for each row and column, and print it all out in a table.

I've used Serge's response in my code, and I've added a calcTotal function to the program, but I'm unsure how to have it print for each column and each row; currently it only prints for one row.

I must also include a printTable function through creating pointers in the getData, calcTotal, and getAverage functions, but I'm unsure how to do so (I'm inexperienced with functions).

I also messed up with the expense.txt file; I edited the file so it can test the program; The file has both strings and floats, but I'm unsure how I would print the array out using both.

This is what the edited expense.txt file that I used looks like; It's the one that the current program I have reads:

434.92 233.76 322.25 1442.98
610.55 233.21 144.75 1232.20 
343.21 224.76 128.90 987.00
278.23 98.43 177.34 899.32 
522.32 109.78 233.45 1232.45  
132.98 221.43 119.56 1090.30 
109.56 342.87 298 1154

This is the original expense.txt that I'm supposed to use:

Department-Name Electric Copier Phone Miscellaneous 
Bookkeeping       434.92 233.76 322.25 1442.98
Sales             610.55 233.21 144.75 1232.20
Service           343.21 224.76 128.90 987.00
Customer-Relations 278.23 98.43 177.34 899.32
Marketing         522.32 109.78 233.45 1232.45
Media             132.98 221.43 119.56 1090.30
Human-Resources   109.56 342.87 298 1154

Here's the edited code:

#include "stdafx.h"
#include <iostream>
#include  <fstream>
#include  <stdlib.h>

using namespace std;

const int ROWSPACE = 7;
const int COLUMNSPACE = 4;
float rowAverage[COLUMNSPACE] = {0}; 
float colAverage[ROWSPACE] = {0};

float getAverage(float averageArray[][COLUMNSPACE], int size, float rowAverage[], float colAverage[]);
float calcTotal(float sumArray[][COLUMNSPACE], int sz, float rowAverage[], float colAverage[]);
void getData(float expense[][COLUMNSPACE], int ROWSPACE);

int _tmain(int argc, _TCHAR* argv[])
{
    float average;
    float total;
    float expenseArray[ROWSPACE][COLUMNSPACE];

    getData(expenseArray,ROWSPACE);
    average=getAverage(expenseArray,ROWSPACE,rowAverage, colAverage);
    cout<<"The average of the expenses is: " << average <<endl<<endl;
    total= calcTotal(expenseArray, ROWSPACE, rowAverage, colAverage);
    cout<<"The total of the expenses is: " << total <<endl<<endl;

    system("pause");
    return 0;
}

float getAverage(float averageArray[][COLUMNSPACE], int size, float rowAverage[], float colAverage[])
{
    int i,j;
    float sum = 0, average;

    for(i = 0; i<size; i++)
    {
        for(j=0; j<COLUMNSPACE; j++)
        {
            sum+=averageArray[i][j]; 
            rowAverage[i] += averageArray[i][j]; 
            colAverage[j] += averageArray[i][j]; 
        }
        rowAverage[i] /= COLUMNSPACE;
    }
    for(j=0; j<COLUMNSPACE; j++) {
        colAverage[j] /= size; 
    }

    average=sum/(size * COLUMNSPACE); 
    return average;
}

float calcTotal(float sumArray[][COLUMNSPACE], int sz, float rowAverage[], float colAverage[])
{
    int i,j;
    float sum = 0, total;

    for(i = 0; i<sz; i++)
    {
        for(j=0; j<COLUMNSPACE; j++)
        {
            sum+=sumArray[i][j]; 
            rowAverage[i] += sumArray[i][j]; 
            colAverage[j] += sumArray[i][j]; 
        }

    total=sum; 
    return total;
    }
}


void getData(float expense[][COLUMNSPACE], int ROWSPACE)
{
    ifstream expenseFile;
    ofstream outFile;
    int i, j;

    expenseFile.open("Expense.txt");
    outFile.open("newFile.txt");

    outFile<<"The expenses are: \n";

    for(i = 0; i<ROWSPACE; i++)
{
    for(j = 0; j<COLUMNSPACE; j++)
    {
        expenseFile>>expense[i][j];
        cout<<expense[i][j]<<"\t"; 
        outFile<<expense[i][j]<<"\t";
    }
    cout << endl; 
    outFile << endl;
    }
}

Answer 1

Let's start with:

for(i = 0; i<ROWSPACE; i++)
{
    for(j = 0; j<COLUMNSPACE; j++)
    {
    expenseFile>>expense[i][j];
    cout<<expense[i][j]<<'\t';
    //                   ^^^^
    outFile<<expense[i][j]<<"\t";
    }
    // now newline
    cout << '\n';
    outfile << '\n';
}

Then you can use std::vector s instead of arrays.

When you calculate the average you are summing all the data and then dividing only by the number of rows. You should limit the sums to the rows or the columns instead.

Answer 2

Well at least you program compiles without warnings, but... it does not meet your requirements!

IMHO your first problem is that you are processing an table of 7 rows of 4 columns and that you declared a table expenseArray[4][7] which normally is 4 rows of 7 columns... Easy to fix as you have nicely declared constants, just write:

const int ROWSPACE = 7;
const int COLUMNSPACE = 4;

But you also need averages per row and column. Just declare

float rowAverage[COLUMNSPACE] = {0}; // initializes the full array to 0...
float colAverage[ROWSPACE] = {0};

and pass them to getAverage:

float getAverage(float averageArray[][COLUMNSPACE], int size,
    float rowAverage[], float colAverage[])
{
    int i,j;
    float sum = 0, average;

    for(i = 0; i<size; i++)
    {
        for(j=0; j<COLUMNSPACE; j++)
        {
            sum+=averageArray[i][j]; // sum for global average
            rowAverage[i] += averageArray[i][j]; // sum for row averages (one value per row)
            colAverage[j] += averageArray[i][j]; //sum for column averages
        }
        rowAverage[i] /= COLUMNSPACE; // compute row averages
    }
    for(j=0; j<COLUMNSPACE; j++) {
        colAverage[j] /= size; // compute column averages
    }

    average=sum/(size * COLUMNSPACE); // total number of values is size * COLUMNSPACE
    return average;
}

You now have all your values and you can print your averages

BTW, if you want to print the values as a table when reading (even if IMHO it would nicer to print at the end) just change your cout outputs:

for(i = 0; i<ROWSPACE; i++)
{
    for(j = 0; j<COLUMNSPACE; j++)
    {
        expenseFile>>expense[i][j];
        cout<<expense[i][j]<<"\t"; // one tab after each column
        outFile<<expense[i][j]<<"\t";
    }
    cout << endl; // one line per row
    outFile << endl;
}

Answer 3

I finally got my program working. I don't have the averages and the totals printed onto the array, and I don't have the strings in the array, but that's ok. I'm just glad I got the program working.

#include "stdafx.h"
#include <iostream>
#include  <fstream>
#include  <stdlib.h>

using namespace std;

const int ROWSPACE = 7;
const int COLUMNSPACE = 4;
float rowAverage[ROWSPACE] = {0}; 
float colAverage[COLUMNSPACE] = {0};
float rowTotal[ROWSPACE] = {0}; 
float colTotal[COLUMNSPACE] = {0};


float getAverage(float averageArray[][COLUMNSPACE], int size, float rowAverage[], float colAverage[]);
float calcTotal(float sumArray[][COLUMNSPACE], int sz, float rowTotal[], float colTotal[]);
void getData(float expense[][COLUMNSPACE], int ROWSPACE);
void printTable();

int _tmain(int argc, _TCHAR* argv[])
{
    printTable();//Prints the data.
    system("pause");
    return 0;
}

float getAverage(float averageArray[][COLUMNSPACE], int size, float rowAverage[], float colAverage[])//Finds the sums of the rows and columns.
{
    int i,j;
    float sum = 0, average;

    cout<<"These are the row averages: \n";
    for(i = 0; i<size; i++)
    {
        for(j=0; j<COLUMNSPACE; j++)
        {
            sum+=averageArray[i][j];//Finds the overall average
            rowAverage[i] += averageArray[i][j]; //Finds each row's average
            colAverage[j] += averageArray[i][j]; //Finds each column's average.
        }
        rowAverage[i] /= COLUMNSPACE; 
        cout<<rowAverage[i]<<"\t"; //prints the row averages
    }
    cout<<endl;
    cout<<"These are the column averages: \n";
    for(j=0; j<COLUMNSPACE; j++) 
    {
        colAverage[j] /= size; 
        cout<<colAverage[j]<<"\t"; //prints the column averages
    }

    average=sum/(size * COLUMNSPACE); 
    return average;
}

float calcTotal(float sumArray[][COLUMNSPACE], int sz, float rowTotal[], float colTotal[])
{
    int i,j;
    float sum = 0, total;

    cout<<"These are the row totals: \n";
    for(i = 0; i<sz; i++)
    {
        for(j=0; j<COLUMNSPACE; j++)
        {
            sum+=sumArray[i][j]; //Finds the overall total
            rowTotal[i] += sumArray[i][j]; //Finds the row totals
            colTotal[j] += sumArray[i][j]; //Finds the column totals
        }
        cout<<rowTotal[i]<<"\t"; //prints out row totals
    }
    cout<<"\nThese are the column totals: \n"; 
    for(j=0; j<COLUMNSPACE; j++) {
        cout<<colTotal[j]<<"\t"; //Prints out column totals
    }

    total=sum; 
    return total;
}

void getData(float expense[][COLUMNSPACE], int ROWSPACE)
{
    ifstream expenseFile;
    ofstream outFile;
    int i, j;

    expenseFile.open("Expense1.txt"); //reads in the file
    outFile.open("newFile.txt"); //creates thew new file

    outFile<<"The expenses are: \n";

    for(i = 0; i<ROWSPACE; i++) //creates the array from the file
{
    for(j = 0; j<COLUMNSPACE; j++)
    {
        expenseFile>>expense[i][j];
        cout<<expense[i][j]<<"\t"; 
        outFile<<expense[i][j]<<"\t";
    }
    cout << endl;  //closes the expense file
    outFile << endl; //closes the new file
    }
}

void printTable() //prints out the data
{
    float average;
    float total;
    float expenseArray[ROWSPACE][COLUMNSPACE];
    getData(expenseArray,ROWSPACE);
    cout<<endl;
    average=getAverage(expenseArray,ROWSPACE,rowAverage, colAverage);
    cout<<endl;
    total= calcTotal(expenseArray, ROWSPACE, rowTotal, colTotal);
    cout<<endl;
}