Help With Pointers

[98dodgeneondohc]

I'm making a program that would do something like this:


Enter the mark out of 10 for a set of 20 students:

7 6 9 4 7 7 5 10 8 6 5

Below is the chart of number of students vs mark out of 10


Number Of
Students
10| *
9| *
8| *
7| *
6|
5| *
4| *
3| *
2| *
1| *
0|
-------------------------------------------
0 1 2 3 4 5 6 7 8 9 10
(Marks out of 10)
Please note that the stars will not line up properly in this post, but you all get the idea. The stars is suppose to go to the intersection of the Number of the Student, and his/her mark.

I made an array of 10 ints. Now I'm guessing that the *'s in the chart will be entered by using pointers? Since I'm not too familiar with pointers, please someone give me an example of how to do this.

And the with the chart itself, I just use printf() to enter them in a fixed location? ex:

printf("\n");
printf("\n");
printf("Number of\n");
printf("Students\n");
printf("\n");
printf("10|\n");
printf("\n");
printf("9 |\n");
printf("\n");
printf("8 |\n");
printf("\n");
printf("7 |\n");
printf("\n");
printf("6 |\n");
printf("\n");
printf("5 |\n");
printf("\n");
printf("4 |\n");
printf("\n");
printf("3 |\n");
printf("\n");
printf("2 |\n");
printf("\n");
printf("1 |\n");
printf("\n");
printf("0 |\n");
printf("   --------------------------------------------------------------\n");
printf("   0     1     2     3     4     5     6     7     8     9     10\n");
printf("                                   Mark (10)                     \n");

I am very new at this so please bare with me. I do apologize that my questions may seem stupid since this work may seem very easy from your standards.

[joshdick]

I don't think you really need pointers for this.

If you're trying to draw a little histogram in ASCII, just draw n asterisks across to get a bar that's n units long.

[misplaced]

i think he want's to input data
http://faq.cprogramming.com/cgi-bin/...&id=1043284385

[98dodgeneondohc]

I don't think you really need pointers for this.

If you're trying to draw a little histogram in ASCII, just draw n asterisks across to get a bar that's n units long.

I don't understand what u mean. Please give me an example.

[98dodgeneondohc]

Guys, what I need to know is how I will take the marks (entered by the user), and enter it in the chart.

I know how to read inputs from the user. I just don't know how to output them on the chart, in the proper spot.

For example, say the user enters 9, 8, 10 etc... the they all go into the array that I made --> int marks[10]

Now I need to take those marks from the array, then enter them into the chart as a --> * , in their proper location of coarse. So if the First student gets 9 (mark), the * will appear in the intersection of Number Of Students: 1 and Marks: 9

[joshdick]

Just output 8 spaces before the asterisk to put it in the ninth position.

Perhaps you could use a 2-D char array to hold the grid of asterisks and spaces. Initialise the array with all spaces. Then, when the first student gets a 9 mark, just array[9][1] = '*';

When you're done with filling in those amounts, output the 2-d array using a nested for loop.

[Dave_Sinkula]

#include <stdio.h>

int main(void)
{
   int i, j, mark[] = {7,6,9,4,7,7,5,10,8,6,5};
   for ( i = 0; i < sizeof mark / sizeof *mark; ++i )
   {
      printf("%2d|", i + 1);
      for ( j = 0; j < mark[i]; ++j )
      {
         fputs("  ", stdout);
      }
      puts("*");
   }
   puts("  +----------------------");
   puts("   0 1 2 3 4 5 6 7 8 9 10");
   return 0;
}

/* my output
 1|              *
 2|            *
 3|                  *
 4|        *
 5|              *
 6|              *
 7|          *
 8|                    *
 9|                *
10|            *
11|          *
  +----------------------
   0 1 2 3 4 5 6 7 8 9 10
*/

[joshdick]

Or you could just wait till someone codes it for you

[98dodgeneondohc]

#include <stdio.h>

int main(void)
{
   int i, j, mark[] = {7,6,9,4,7,7,5,10,8,6,5};
   for ( i = 0; i < sizeof mark / sizeof *mark; ++i )
   {
      printf("%2d|", i + 1);
      for ( j = 0; j < mark[i]; ++j )
      {
         fputs("  ", stdout);
      }
      puts("*");
   }
   puts("  +----------------------");
   puts("   0 1 2 3 4 5 6 7 8 9 10");
   return 0;
}

/* my output
 1|              *
 2|            *
 3|                  *
 4|        *
 5|              *
 6|              *
 7|          *
 8|                    *
 9|                *
10|            *
11|          *
  +----------------------
   0 1 2 3 4 5 6 7 8 9 10
*/

How would I modify this array so that it instead takes the values from the user input?

[98dodgeneondohc]

#include <stdio.h>

int main(void)
{
   int i, j, mark[] = {7,6,9,4,7,7,5,10,8,6,5};
   for ( i = 0; i < sizeof mark / sizeof *mark; ++i )
   {
      printf("%2d|", i + 1);
      for ( j = 0; j < mark[i]; ++j )
      {
         fputs("  ", stdout);
      }
      puts("*");
   }
   puts("  +----------------------");
   puts("   0 1 2 3 4 5 6 7 8 9 10");
   return 0;
}

/* my output
 1|              *
 2|            *
 3|                  *
 4|        *
 5|              *
 6|              *
 7|          *
 8|                    *
 9|                *
10|            *
11|          *
  +----------------------
   0 1 2 3 4 5 6 7 8 9 10
*/

mark[] = {7,6,9,4,7,7,5,10,8,6,5};

How would I modify this array so that it instead takes the values from the user input?

[Dave_Sinkula]

Or you could just wait till someone codes it for you

Is 3 lines of code really going overboard and giving away the farm? Or 11 lines if you consider the full context? Maybe there's 50 lines total if you count an example of how to preserve whitespace using code tags.

I don't understand what u mean. Please give me an example.

Guys, what I need to know is how I will take the marks (entered by the user), and enter it in the chart.

I know how to read inputs from the user. I just don't know how to output them on the chart, in the proper spot.

For example, say the user enters 9, 8, 10 etc... the they all go into the array that I made --> int marks[10]

Now I need to take those marks from the array, then enter them into the chart as a --> * , in their proper location of coarse. So if the First student gets 9 (mark), the * will appear in the intersection of Number Of Students: 1 and Marks: 9

[Dave_Sinkula]

How would I modify this array so that it instead takes the values from the user input?

Declare the array with some size, say mark[20], then loop through and obtain each.

[swoopy]

mark[] = {7,6,9,4,7,7,5,10,8,6,5};

How would I modify this array so that it instead takes the values from the user input?

I know how to read inputs from the user.

Then again, maybe not.

[98dodgeneondohc]

Then again, maybe not.

I meant I know how to read inputs from users such as using scanf(), fgets() etc... then assigning those values to variables. I am not really familiar with assigning integer values into int arrays by using one of the functions i mentioned above.

[quzah]

array[ something ] = somevalue;

I'd suggest you get yourself a good C book and start from the beginning. It's not a race. Just pay attention and don't continue on to the next lesson until you fully understand the one you're on.

Quzah.