Finding Lowest/Highest in Multi-dimensional Array

[danielmtnz]

I have this multi-dimensional array. There are 12 rows, each represents the months, and 2 columns, the 1st column represents the lowest temperature and the 2nd column represents the highest temperature.

I need to find the lowest temperature in only the first column and the highest in only the 2nd column. How would I go about this?

This takes in the temperatures. LOHI = 2, MONTHS = 12, LOW = 0, HIGH = 1

void PopulateTemp(int temp[][LOHI])
{
	for(int month = 0; month < MONTHS; month++)
	{
		cout << "Month " << month+1 << endl;
		temp[month][LOW] = ReadTemp("   LOW: ");
		temp[month][HIGH] = ReadTemp("   High: ");
        
		while (temp[month][HIGH] < temp[month][LOW])
		{
			cout << "   -- Low must be lower than high. Derp!" << endl;
			temp[month][LOW] = ReadTemp("   LOW: ");
			temp[month][HIGH] = ReadTemp("   High: ");
		}
	}
}

Here is my approach to it:

int FindLow(const int temp[][LOHI])
{
    int low = temp[0][0];
    
    for(int i = 0; i < 1; i++)
    {
        for(int j = 0; j < MONTHS; j++)
        {
            if(temp[i][j] < low)
            {
                low = temp[i][j];
                return low;
            }
        }
    }
}

My professor said we only needed 1 for loop as you only need to read the data from one column in each?

Thank you.

[MiiNiPaa]

for(int j = 0; j < MONTHS; j++) {
    if(temp[i][0] < low) {
        low = temp[i][0];
    }
    if (temp[i][1] > high) {
        high = temp[i][1]
    }
}

[danielmtnz]

@MiiNiPaa Is that suppose to be only 1 loop? Because you're using j and i in the same loop.

Also, that doesn't seem to work as it always just gives me the first input which is temp[0][0].

Here is how I'm doing it:

int FindLow(const int temp[][LOHI])
{
    int low = temp[0][0];
    
    for(int j = 0; j < MONTHS; j++) {
        if(temp[j][0] < low) {
            low = temp[j][0];
        }
    }
    return low;
}

And how will I cout it? Like this:

void ReportTemp(const int temp[][LOHI], int low)
{

    cout << "Lowest: " << temp[low][0];
}

or just

cout << "Lowest: " << low;
?

[MiiNiPaa]

change all i to j. I was distracted midway and made a mistake.
In low variable you store the value of lowest temperature, not index, so you should just do std::cout << "Lowest: " << low;

Maybe temp[0][0] is the lowest temperature?

[danielmtnz]

I figured, so I changed them. However, that did not help me find the lowest value. I am making sure that the lowest input is not in temp[0][0] but it keeps returning that for the value of low.

Maybe it has something to do with initializing low to = temp[0][0]? And the value of low is never changed?

[MiiNiPaa]

Show your code

[danielmtnz]

To find low:

int FindLow(const int temp[][LOHI])
{
    int low = temp[0][0];
    
    for(int j = 0; j < MONTHS; j++)
    {
        if(temp[j][0] < low)
        {
            low = temp[j][0];
        }
    }
    return low;
}
}

and it is being outputted here:

void ReportTemp(const int temp[][LOHI], int low)
{
	const string MONSTR[MONTHS] = {"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul",
		"Aug", "Sep", "Oct", "Nov", "Dec"};
    
	cout << endl;
	cout << "FULLERTON" << endl;
	cout << "MONTH" << setw(4) << "|" << setw(6) << "LOW" << setw(2) << "|" << setw(6)
    << "HIGH" << " |" << endl;
    
	for(int i = 0; i < MONTHS; i++)
	{
		cout << MONSTR[i] << setw(6) << "|";
		for(int j = 0; j < LOHI; j++)
		{
			cout << setw(6) << temp[i][j] << setw(2) << "|";
		}
		cout << endl;
	}
    cout << "Lowest: " << low;
}

The way it is now, it is just outputting 0 for low every time.

[MiiNiPaa]

And how these functions are used?
Because FindLow function works fine. I have tested it.

[danielmtnz]

Here's the whole program:
[code]
#include <iostream>
#include <iomanip>
#include <string>
using namespace std;

const int MONTHS = 12;
const int LOHI = 2;
enum{LOW, HIGH};

void PopulateTemp(int temp[][LOHI]);
int ReadTemp(string prompt);
int FindLow(const int temp[][LOHI]);
void ReportTemp(const int temp[][LOHI], int low);

template <class T>
bool Read(T& d);

int main()
{
int temp[MONTHS][LOHI];
int low;

low = FindLow(temp);

PopulateTemp(temp);
ReportTemp(temp, low);

return 0;
}

It asks the user to enter a low and high temperature for each month and at the end I'm suppose to output the lowest temperature under the low column and the highest temperature under the high column.

[MiiNiPaa]

In your main(): You are finding lowest value in uninitializated array and then inialize it. Don't you think it should be other way around?

[danielmtnz]

@MiiNiPaa Wow! I was so focused on the function it self that I completely forgot about main. You were right,

I had to call FindLow() after PopulateTemp(). Thank you very much.