Perl program needed to predict size of populatio of organisms. Program needs to use loop for output.

Question

[Sidney]

print"Please enter the starting number of organisms:";
$organisms=<STDIN>;
chomp($organisms);
}

print"Please enter the average daily population increase (as a percentage):";
$increase_perc=<STDIN>;
chomp($increase_perc);

if ($increase_perc==0) {}

print"Please enter the number of days they will multiply:";
$days=<STDIN>;
chomp($days);
}

$count=$organisms;
foreach ($days){
    $count++;
    if ($days==1) {
        print"Day\tOrganisms\n\n";
        print"---------------------\n\n";
        print"1\t\t$organisms\n";
    }
    if ($days==2) {
        $result=int(($organisms * $increase_perc)/100)+$organisms;
        $count++;
        print"Day\tOrganisms\n\n";
        print"---------------------\n\n";
        print"1\t\t$organisms\n";
        print"2\t\t$result\n";
    }
    if ($days==3) {
        $result3=int($result)+$organisms;
        print"Day\tOrganisms\n\n";
        print"---------------------\n\n";
        print"1\t\t$organisms\n";
        print"2\t\t$result\n";
        print"3\t\t$result3\n";
    }
    if ($days==4) {
        my$result_4=($line3 + $organisms)+ $organisms;
        $line4=($result + $organisms) * 4;
        print"Day\tOrganisms\n\n";
        print"---------------------\n\n";
        print"1\t\t$organisms\n";
        print"2\t\t$line\n";
        print"3\t\t$line3\n";
        print"4\t\t$line4\n";
    }
}

None of my output is working. Please help

Output should be:

Day          Organisms
-----------------------------
1            2.0
2            3.0
3            4.5
4            6.75
5            10.125
6            15.1875
7            22.78125

Answer 1

[russhh]

foreach($days)

is wrong. You could use

while($count < $days){$count++; ... logic ...}

To see why foreach($scalar) is wrong type this example into your command line:

perl -le 'foreach(10){print $_}'

with 10 as a scalar and compare with the following:

perl -le 'foreach(1..10){print $_}'

where the numbers are treated in list context.

Nonetheless, there are other issues that you will have to address..

[Sidney]

Thanks for looking at my question. I have updated the program to reflect the change you indicated: while($count < $days){$count++}

But I'm still not sure how to format the output, without repeating each value over and over?

[russhh]

is this an assignment? It certainly sounds like one, since this problem would typically be solved analytically. I'm afraid I shall not be giving you anymore help

[Sidney]

I am simply trying to understand how I can go about solving the problem. Any direction you can point me in would be greatly appreciate. I am not looking for an answer, but a way I can solve this on my own. When you said there are other issues, could you please explain?

[russhh]

Try writing a program using a while loop or a for loop but without any if / else that prints out the folowing (with the header):

THE NUMBERS FROM 1 TO 5
1
2
3
4
5

[Biomonika (Noolean)]

Maybe you could go through couple of "Introduction to Perl" manuals before trying to solve real problems and asking for help.