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Two-Dimensional Array that stores integers. How can I show the index of the highest temp and lowest temp?

Posted on 2008-10-29
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Im trying to complete an assignment and am stuck on two parts.

With the code listed below, I need to add two additional functions named indexHighTemp and indexLowTemp.

indexLowTemp: This function needs to return the index of the highest high temperature in the array.
indexHighTemp: This function needs to return the index of the lowest low temperature in the array.

I'd like to add these functions to the code listed below, with minimal intrusions.
``````#include <iostream>

#include <iomanip>

#include <string>

using namespace std;

const int rows =2;

const int columns =12;

string month[] = {"January", "Feburary", "March",

"April", "May", "June", "July",

"August", "September", "October",

"November", "December"};

void getData();

double averageHigh(int matrix[rows][columns]);

double averageLow(int matrix[rows][columns]);

int row;

int col;

int matrix[rows][columns];

int counter = 0;

int maxIndex = 0;

int main()

{

double highaverage;

double lowaverage;

for(row = 0; row<rows; row++)

for(col =0; col < columns; col++)

matrix[row][col] = 0;

getData();

highaverage = averageHigh(matrix);

cout<<"The average of the high temperatures is "<<highaverage<<endl;

lowaverage = averageLow(matrix);

cout<<"The average of the low temperatures is "<<lowaverage<<endl;

system("pause");

return 0;

}

void getData()

{

cout<<"Please Enter the Highest Temperature for each month: "<<endl;

row = 0;

for(col = 0; col<columns; col++)

{

cout << month[col] << ": ";

cin>>matrix[row][col];

}

cout<<"Please Enter the Lowest Temperature for each month: "<<endl;

row = 1;

for(col = 0; col<columns; col++)

{

cout << month[col] << ": ";

cin>>matrix[row][col];

}

}

double averageHigh(int matrix[rows][columns])

{

double average=0;

int sum = 0;

row = 0;

for(col =0; col<columns; col++)

sum = sum + matrix[row][col];

average = sum / 12;

return average;

}

double averageLow(int matrix[rows][columns])

{

double average=0;

int sum =0;

row =1;

for(col =0; col<columns; col++)

sum = sum + matrix[row][col];

average = sum / 12;

return average;

}
``````
0
Question by:tomsterkw
• 3
• 2

LVL 16

Expert Comment

I assume your problem is that the array is two dimensional, but a function can only return one thing.

You have two options.  Define a struct with two integers and return a structure, or return a single integer that is equal to the location of the desired item as if it were a one dimensional array.

In other words, for an array of matrix[rows][cols], that is equal to an array of matrix2[rows*cols], and the item at matrix[x][y] would be at matrix2[(x-1)*size of an element + col], (basically, it's possible to specify an element in a multi-dimensional array with a single value).
0

Author Comment

Thanks HooKoo for the quick response!

I think the first option would work fine, seeing how High temps are assigned to matrix[0][rows] and Low temps are stored in matrix[1][rows]. Could I simply utilize two for loops and send the results back to main? If so, think you could lend me a hand code wise?

I was thinking something like below but I cant seem to get it to work right. I think my logic is a little fubar also.

for (counter = 0; counter < 12; counter++)
{
if (matrix[0][colums] < max)
max = matrix[0][colums]
}
0

LVL 16

Expert Comment

Hopefully the 'struct' idea is self explanatory, but here's an example of treating the data as a single dimenstional array.
The concept is to allow access to the 2D array via a 1D array, then define a function that can return the offset of the desired item in the 1D array.
``````int indexLowTemp(int matrix[rows][columns])

{

int LowTemp = matrix[0][0];

int rc = 0; //Return Code - single digit index to matrix

int row;

int col;

for( row=0; row < rows; row++ )

{

for( col=0; col < cols; col++ )

{

if( matrix[row][col] < LowTemp )

{

LowTemp = matrix[row][col];

rc = row * rows + col;

}

}

}

return rc;

}

/* To get the value of the lowest temp */

int* pmatrix = &matrix;  //Pointer to matrix[0][0];

int LowTemp = *pmatrix[ indexLowTemp( matrix ) ];

/* Bonus, decode the row/col from the return of indexLowTemp */

int index = indexLowTemp( matrix );

int row = index / rows;

int col = index % rows;
``````
0

LVL 16

Accepted Solution

HooKooDooKu earned 50 total points
struct example

And careful about getting your row/col backwards.  The latest post you were using [row] as the 2nd dimension, but all of your code so far is using [row] for the 1st dimension.
``````struct rowcol

{

int row;

int col;

};

struct rowcol indexLowTemp(int matrix[rows][columns])

{

int LowTemp = matrix[0][0];

struct rc;

rc.row = 0;

rc.col = 0;

int row;

int col;

for( row=0; row < rows; row++ )

{

for( col=0; col < cols; col++ )

{

if( matrix[row][col] < LowTemp )

{

LowTemp = matrix[row][col];

rc.row = row;

rc.col = col;

}

}

}

return rc;

}

/* To get the value of the lowest temp */

struct rowcol rc = indexLowTemp( matrix );

int LowTemp = matrix[ rc.row ][ rc.col ];

``````
0

Author Closing Comment

Thank you very much for your assistance!
I was really close by the time that I noticed this post. Your assistance helped confirm that I was on the right track.  I appricaite the timely reply.
0

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