Thread: Help with Counting values in Arrays

Hello all, I was hoping to get a little help for some code I'm writing. I have to declare an array of 20 integers, fill the array with random numbers between 1-6, and then write a loop to count how many times each of the values appear in the array. Also I have to use an array of 6 elements to keep track.

This is what I have so far. Any help would be appreciated.

Code:

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

main() {

	int random[20];
	int occur[6];
	int i;
	srand(time(NULL));

	for(i = 0; i < 20; i++)
	{
		random[i] = rand() % 6 + 1;
	}
		


	for (i = 0; i < 10; i++) 
	{

		if (random[i] == 6)
			occur[i]++;


	}
	


	system("pause");
}

It's looking very good so far, well done on that.

main should be declared as int main( void ) as it takes no arguments and returns an integer to the operating system.

The part where you're generating the random numbers and placing them in the array looks good.

To count occurences in an array you put the frequency of the first thing in the first element, the frequency of the second thing in the second element, so on. Thinking of this, what would be appropriate to use as an array index into 'occur'?

Also, you're going to need to go through each element to be able to count the frequency of the numbers, so I'm not quite sure where you pulled 10 from.

Originally Posted by Vontrapp

Hello all, I was hoping to get a little help for some code I'm writing. I have to declare an array of 20 integers, fill the array with random numbers between 1-6, and then write a loop to count how many times each of the values appear in the array. Also I have to use an array of 6 elements to keep track.

This is what I have so far. Any help would be appreciated.

Code:

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

main() {    // should be main (void) as you stated

	int random[20];
	int occur[6];
	int i;
	srand(time(NULL));

	for(i = 0; i < 20; i++)
	{
		random[i] = rand() % 6 + 1;
	}
		


	for (i = 0; i < 10; i++)  // This should be for (i = 0; i < 20; i++), typo on my part
	{

		if (random[i] == 6)
			occur[i]++;


	}
	


	system("pause");
}

unfortunately I didn't quite grasp your explanation about counting occurrences.

Code:

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

main(void) {

	int random[20];
	int occur[7];
	int i;
	srand(time(NULL));

	for(i = 0; i < 20; i++)
	{
		random[i] = rand() % 6 + 1;
	}
		

	for (i = 0; i < 20; i++) 
	{

	occur[random[i]]++;
	
	}

	for (i = 0; i < 7; i ++)
	
		
		printf("%i\n\n",occur[i]);  
	


	system("pause");
}

I'm getting wacky numbers when I run this:


-858993460

-858993459

-858993456

-858993454

-858993455

-858993459

-858993457

Press any key to continue . . .

Enable your compiler warning.
for gcc , use -Wall flag.

So many errors I found in your program.It seems that you should spend more time on your book.

Undoubtedly true, and welcome to the forum, zhangzhongke007.

awesome!! Thanks everyone for your help.

LOL you know what else too, sometimes looking at code for sooooo long you don't even see where your mistakes are. Just like writing a paper and not catching certain grammatical errors. This is pretty much new to me but I am absorbing a lot of information but once again thanks everyone for your help.