Thread: problem printing histogram about number frequencies

hello everyone ...

i have this program .. i tried to make it work to give me this result
output:

Code:

input array {1,3,5,1,1,8,6,6,1,3,2,1,6,8,8}
[0]
[1] *****
[2]*
[3]**
[4]
[5]*
[6]***
[7]
[8]***
[9]

this is my code

Code:

Code:

int main ( void )
{
   int i, n,j;
   
   printf ("How many values in your data set? ");
   scanf ("%d", &n);

   int list[n];
   for (i=0; i < n; i++) {
      printf ("Enter a value: ");
      scanf ("%d", &list[i]);
      
   }

   
   int hist[10];    


   
   printHistogram ( hist, 10);
  
   return 0;
}

void printHistogram ( int *list, int n )
{
    int i, j;

   for (i=0; i < n; i++) {
      printf ("[%d] ", i);
      for (j = 1; j <= list[i]; j++)
         printf ("*");
      printf("\n");
    }
   
}

instead i'm having asterisks at the end of the output

can you please help me ....
thank you ..

Originally Posted by AndrewHunter

Do you know what you are doing at all or are you just randomly cutting and pasting code from various places? These questions are ridiculous between this post and your other one.

1. What is the point in int hist[10]?
2. Why do you store all of your input into the list array but then pass the hist array to your print function?
3. WHERE DID YOU STEAL THIS CODE FROM AND WHY ARE YOU NOT CODING YOURSELF?
4. Which university in India are you going to?

Ok that is about all the questions I have for now.

i have read some of your replies to other people ... you don't have to insult people every time
answering your questions :
i didn't steal any one's code ( you always say that in your posts )
this code is given to me as an assignment and i should correct it .. if you notice unlike my previous program i didn't say i wrote it .. so relax .. plus i'm not India!

so now i understand there is not point of

Code:

int hist [10]

i deleted this tricky addition ..
and fix the code to :

Code:

void  printHistogram ( int *hist, int n );

int main ( void )
{
   int i, n,j;
   

   
   printf ("How many values in your data set? ");
   scanf ("%d", &n);

  int list[n];
   for (i=0; i < n; i++) {
      printf ("Enter a value: ");
      scanf ("%d", &list[i]);
      
   }   
       
   printHistogram ( list, n);
   
   return 0;
}

void printHistogram ( int *list, int n )
{
    int i, j;

    for (i=0; i < n; i++) {
      printf ("[%d] ", i);
      for (j = 1; j <= list[i]; j++)
         printf ("*");
      printf("\n");
    }
   
}

i get this as an output:

Code:

Code:

How many values in your data set? 6
¼¼§ÏEnter a value: 1
¼¼§ÏEnter a value: 1
¼¼§ÏEnter a value: 3
¼¼§ÏEnter a value: 5
¼¼§ÏEnter a value: 6
¼¼§ÏEnter a value: 3
ÏϧÏ[0] *
ÏϧÏ[1] *
ÏϧÏ[2] ***
ÏϧÏ[3] *****
ÏϧÏ[4] ******
ÏϧÏ[5] ***

anyone can explain how can i count the frequency of each number by adding asterisks ??
thank you ..

Originally Posted by AndrewHunter

You need to look at your entry loop:

Code:

 for (i=0; i < n; i++) {
      printf ("Enter a value: ");
      scanf ("%d", &list[i]);
}

All this does is put values into the array. The layout of the buckets for your histogram is a one to one mapping with the element numbers of your array, e.g. bucket 1 is at array[1]. So how would you increment each bucket depending on input? Can you describe this in words?

by using a sort of counter ?
I'm thinking about a new counter array but i'm still thinking how to use it

Ok I'm sure that i should use a counter after reading each number into the array. the counter must be

Code:

int count[i]=0;
.
.
.
after reading into array
count[i]++;

then use it in for loop and print the asterisks based on this counter...
am i right here ?
i tried to make this work...it just didn't

hello again ..
as i said i tried to declare a new array called freq .. to count the frequencies of each number enters the array
here is what i have :

Code:

void  printHistogram ( int *hist,int freq[], int n );
int main ( void )
{
   int i, n,j;
   
   printf ("How many values in your data set? ");
   scanf ("%d", &n);

   int list[n];
   int freq
[list]=0;
   
   for (i=0; i < n; i++) {
      printf ("Enter a value: ");
      scanf ("%d", &list[i]);
     freq
[list[i]]++:
            
   }
   
   printHistogram ( list,10);
 
   return 0;
}

void  printHistogram ( int *hist,int freq[], int n );
{
    int i, j;

    for (i=0; i < n; i++) 
    {
      printf ("[%d] ", i);
      for (j = 1; j <= freq
[list[[i]]; j++)
         printf ("*");
      printf("\n");
    }
   
}

but it's not working
if any one has any idea how to fix this code ..
reminder : i didn't write this code .. it's written by the professor and i should correct to make it work..
thanks ..

Originally Posted by WoodSTokk

double post with Chromium ??? sorry.

thanks I fixed it ..
but still not working

Make sure your code is neatly formatted and indented. And "paste as text" so the forum formatting can do its own thing. This is closer to what your code should look like:

Code:

#include <stdio.h>

void printHistogram ( int *hist,int freq[], int n );

int main ( void )
{
    int i, n,j;

    printf ("How many values in your data set? ");
    scanf ("%d", &n);

    int list[n];
    int freq[list]=0;

    for (i=0; i < n; i++) {
        printf ("Enter a value: ");
        scanf ("%d", &list[i]);
        freq[list[i]]++:
    }

    printHistogram ( list,10);

    return 0;
}

void printHistogram ( int *hist,int freq[], int n );
{
    int i, j;

    for (i=0; i < n; i++)
    {
        printf ("[%d] ", i);
        for (j = 1; j <= freq[list[[i]]; j++)
            printf ("*");
        printf("\n");
    }
}

Did you try compiling and running your program? (I doubt it.) Let us know exactly what problems you're having.

Code:

int freq[list]=0;

Explain to us what you think this line does.

Line 26: You're not supposed to have a semi-colon after the function definition.

Originally Posted by Matticus

Make sure your code is neatly formatted and indented. And "paste as text" so the forum formatting can do its own thing. This is closer to what your code should look like:

Code:

#include <stdio.h>

void printHistogram ( int *hist,int freq[], int n );

int main ( void )
{
    int i, n,j;

    printf ("How many values in your data set? ");
    scanf ("%d", &n);

    int list[n];
    int freq
[list]=0;

    for (i=0; i < n; i++) {
        printf ("Enter a value: ");
        scanf ("%d", &list[i]);
        freq
[list[i]]++:
    }

    printHistogram ( list,10);

    return 0;
}

void printHistogram ( int *hist,int freq[], int n );
{
    int i, j;

    for (i=0; i < n; i++)
    {
        printf ("[%d] ", i);
        for (j = 1; j <= freq
[list[[i]]; j++)
            printf ("*");
        printf("\n");
    }
}

Did you try compiling and running your program? (I doubt it.) Let us know exactly what problems you're having.

Code:

int freq
[list]=0;

Explain to us what you think this line does.

Line 26: You're not supposed to have a semi-colon after the function definition.

yes i fixed these errors ( semicolons , arguments ..)
this is the code

Code:

 void  printHistogram ( int *hist,int freq, int n );

/**
 * This program requests data from the user and then
 * computes and prints a histogram. You may assume that
 * the data values entered are in the range of 0 to 9.
 */
int main ( void )
{
   int i, n,j;
   

   // Data entry
   //
   printf ("How many values in your data set? ");
   scanf ("%d", &n);

   int list[n];
   int freq
[list[n]];
   
   for (i=0; i < n; i++) {
      printf ("Enter a value: ");
      scanf ("%d", &list[i]);
     freq
[list[i]]++;
            
   }

   // Processing data to compute histogram
   
       


   // Printing histogram
   printHistogram ( list,freq,10);
 
   
   return 0;
}

void  printHistogram ( int *hist,int freq, int n )
{
    int i, j;

    for (i=0; i < n; i++) 
    {
      printf ("[%d] ", i);
      for (j = 1; j <= freq
[list[i]]; j++)
         printf ("*");
      printf("\n");
    }
   
}

i got two errors and a warning:

Code:

Code:

Ïhistogram.c:42:24: warning: 
ÏÏ§Ï      incompatible
ÏÏ§Ï      pointer
ÏÏ§Ï      to
ÏÏ§Ï      integer
ÏÏ§Ï      conversion
ÏÏ§Ï      passing
ÏÏ§Ï      'int
ÏÏ§Ï      
[list[n]]'
ÏÏ§Ï      to
ÏÏ§Ï      parameter
ÏÏ§Ï      of
ÏÏ§Ï      type
ÏÏ§Ï      'int'
ÏÏ§Ï      [-Wint-conversion]
ÏÏ§Ï  ...freq...
ÏÏ§Ï     ^~~~
ϼ§Ïhistogram.c:9:39: note: 
ÏÏ§Ï      passing
ÏÏ§Ï      argument
ÏÏ§Ï      to
ÏÏ§Ï      parameter
ÏÏ§Ï      'freq'
ÏÏ§Ï      here
ÏÏ§Ï  ...fr...
ÏÏ§Ï     ^
ϼ§Ïhistogram.c:55:29: error: 
ÏÏ§Ï      use
ÏÏ§Ï      of
ÏÏ§Ï      undeclared
ÏÏ§Ï      identifier
ÏÏ§Ï      'list';
ÏÏ§Ï      did
ÏÏ§Ï      you
ÏÏ§Ï      mean
ÏÏ§Ï      'hist'?
ÏÏ§Ï  ...list...
ÏÏ§Ï     ^~~~
ÏÏ§Ï     hist
ϼ§Ïhistogram.c:48:29: note: 
ÏÏ§Ï      'hist'
ÏÏ§Ï      declared
ÏÏ§Ï      here
ÏÏ§Ï  ...*h...
ÏÏ§Ï      ^
ϼ§Ïhistogram.c:55:28: error: 
ÏÏ§Ï      subscripted
ÏÏ§Ï      value
ÏÏ§Ï      is
ÏÏ§Ï      not
ÏÏ§Ï      an
ÏÏ§Ï      array,
ÏÏ§Ï      pointer,
ÏÏ§Ï      or
ÏÏ§Ï      vector
ÏÏ§Ï  ...freq
[list[i]...
ÏÏ§Ï     ~~~~^~~~~~~~
ÏϧÏ1 warning and 2 errors generated.
ÏϧÏ

about your question :
i was thinking about freq
[list[i]] as a counter for each entry in the element to count the frequency

Hi Hana

Try making it incrementally. Assume that all inputs are going to be between 1-10 (both inclusive), doesn't matter how many they are but what values they are you need.

As for printing histogram,

Now you know what your inputs are (from 1 - 10). So drop the n from argument.
You can also drop hist, not using it anyway are you?

Run the loop over your freq then for each freq run a loop on its count. you should be good.