sort algorithm is working, but i finding it hard to implement in helpers.c

Question

#include <stdio.h>
#include <cs50.h>

int main(void)
{
int values[12] = {10,2,14,5,7,4,3,13,15,22,8,24};
int i = 0;
int n = 12;   
for(int x = 0; x < n*n; x++)
{
    while(i<n-1)
    {

        if(values[i]>values[i+1])
        {
          int temp = values[i+1];
          values[i+1] = values[i];
          values[i] = temp;
          i++;
          for(int c = 0; c < n; c++)
          {
           printf("%i ",values[c]);
          }
          for(int a = 0; a < 1; a++)
          {
           printf("\n");
          }

        }

        else
        {
        i++;
        }

    }
    while(i >= 5) 
    {
    i=0;
    }   
}
}

So this is basically my bubble sort algorithm. And as it seems it works fine. While implementing it in helpers.c. i use n as a number of how long is array values, and values as an array.

This is how it looks:

/**
 * helpers.c
 *
 * Computer Science 50
 * Problem Set 3
 *
 * Helper functions for Problem Set 3.
 */

#include <cs50.h>

#include "helpers.h"

/**
 * Returns true if value is in array of n values, else false.
 */
bool search(int value, int values[], int n)
{
    // TODO: implement a searching algorithm
    if(n < 0)
     {
     return false;
     }
     else
    {
      for(int i = 0; i < n; i++)
      {
        if(values[i]==value)
        {
        return true;
        }
      }
    }
    return false;
}

/**
 * Sorts array of n values.
 */
void sort(int values[], int n)
{
    int i = 0;
    // TODO: implement an O(n^2) sorting algorithm
    for(int x = 0; x < n*n; x++)
    {
    while(i<n-1)
    {

        if(values[i]>values[i+1])
        {
          int temp = values[i+1];
          values[i+1] = values[i];
          values[i] = temp;
          i++;
          for(int c = 0; c < n; c++)
          {
           printf("%i ",values[c]);
          }
          for(int a = 0; a < 1; a++)
          {
           printf("\n");
           }

        }

        else
        {
         i++;
        }

     }
     while(i >= 5) 
     {
     i=0;
    }   
    }

 }

And then i run ./generate 1000 50 | ./find 127 haystack[996] = haystack[997] = haystack[998] = haystack[999] = haystack[1000] =

Found needle in haystack!

I get his... Haystacks are empty, and sort seems is not executed... How i need to run it or change it for it to work?

Answer 1

I believe the problem is a lack of understanding on how it runs when you execute it this way. It appears that you're concerned that none of the numbers in the haystack are appearing on the screen and you aren't sure whether the sort is running.

"And then i run ./generate 1000 50 | ./find 127" When you execute the program this way, you have to understand what's happening. /find is writing all of it's printf() calls to the screen, but instead of taking the input from the console (keyboard), it is taking input from the piped output generated by ./generate. The numbers are going directly into find from generate, and will not be printed to the screen.

If you're worried that sort isn't working, you could add a small loop to simply print out the haystack array from element 0 in order. If the list was input to the program out of order and the output list is sorted, then it's working. You could go a step further and add code to check that any number in the list is equal to or larger than the previous number.

Unfortunately, my IDE is down, so I can't test.

If this answers your question, please click on the check mark to accept. Let's keep up on forum maintenance. ;-)