Thread: Selection Sort

Originally Posted by Andersonsacanno

fwrite sucks < fprintf rocks

Not that I need to defend fwrite here, but you seem to misunderstand that fwrite and fprintf do two completely different things. fwrite writes the contents of a buffer in memory directly to a file stream, byte for byte. fprintf formats the output as text. Their uses don't overlap much. Generally speaking, fwrite is used for writing to a binary file, and fprintf is used for writing to a text file.

Thank you.


Next up: Reading numbers from file

My friend and I have been able to read the numbers from the file, change them from ascii (char) into ints, then sort them using the same functions I used my original sort and fprintf to a file. I know this code isn't perfect or pretty, but it does take numbers from a file, sort, and then print them to a file.

Code:

#include <stdio.h>
#include <conio.h>
#include <string.h>
void append(char* s, char c)
{
        int len = strlen(s);
        s[len] = c;
        s[len+1] = '\0';
}
void swap (int *a, int *b) 
{
int temp;
temp = *a;
*a = *b;
*b = temp;
}
int sort(int a[], int x)
{
int i, j;
 for (i = -1; i < x-1; i++)
 {
  
 
  for(j=i; j >= 0; j--)
 
  { 
        printf(" if %d > %d \n",a[j], a[j+1]);
   if (a[j] > a[j+1])
   {
        printf("\n\nthen swap them\n");
   swap(&a[j], &a[j+1]);
   }
  }
 }
 
}
int main()
{
    int a;
    int i = 0;
    int x = 100;
    int p = 100;
    int j = 0;
    int q = 100;
    int y = 14;
    int g = 0;
    int numbers[p];
   // memset(numbers, 0, sizeof(int), 100);
    int inner;
    int outer;
    char buffer[x];
    char array[p][q];
  // memset(array, 0, sizeof(array));
  
  for (i = 0; i < 100; i++)
  {
      numbers[i] = 0;
       
      }
      
    
  
    
  FILE *f;
  
 
  if (f = fopen("C:\\users\\hello\\desktop\\test.txt", "rt"))
  {
    fread(buffer, 1,  x, f);
    fclose(f);
    printf("\n%s", buffer);
    
  }
 for (i = 0; i < 100; i++)
 {
     if (buffer[i] >= 48 && buffer[i] <= 56)
     {
     
     append(array[j], buffer[i]);
     
     } 
     else if (buffer[i] == 44)
     {
          j++;
      }
     
      }
     
   
   for (i =0; i < 10; i++)
     {
         printf("\n Spot %d: \n %s \n\n", i, array[i]);
         }
        
         
         
   for(outer = 0; outer < 10; outer++)
{
for(inner = 0; inner < 10; inner++)
{
       int digit = 1;
       
        
      if (array[outer][inner] == 48)
      {
             digit = 0;       } 
            
      else if (array[outer][inner] == 49)
      { 
             digit = 1;       } 
      else if (array[outer][inner] == 50)
      { 
             digit = 2;       } 
      else if (array[outer][inner] == 51)
      { 
             digit = 3;       } 
      else if (array[outer][inner] == 52)
      { 
             digit = 4;       } 
      else if (array[outer][inner] == 53)
      { 
             digit = 5;       } 
      else if (array[outer][inner] == 54)
      { 
             digit = 6;       }
      else if (array[outer][inner] == 55)
      { 
             digit = 7;       } 
      else if (array[outer][inner] == 56)
      {
             digit = 8;       } 
      else if (array[outer][inner] == 57)
      { 
             digit = 9;       } 
      else
      {break;}
      printf("\n\nThe current digit is %d, and the current value in numbers[outer] is %d",digit, numbers[outer]);
       numbers[outer] = numbers[outer]*10 + digit;
             printf("\nin number %d, in digit %d, i found value %d",outer,inner, digit);
      
       
      
       }
       
     printf("the final integer is %d\n", numbers[outer]);
       }
sort(numbers, length);
printf("Final array is : \n");
for(i = 0; i < 10; i++)
{
printf(" %d, ",numbers[i]);
}
printf("\n\n");
FILE *fp;
fp=fopen("c:\\users\\hello\\desktop\\test1.txt", "w");
for (i = 0; i < 10; i++){
fprintf (fp, "%d, ", numbers[i]);
}       
         
system("Pause");
  return 0;
}

You know that C has functions that do that for you, right?

strtoi, strtol, strtod, etc.

I'm curious why not convert the strings to numbers with fscanf() using a "%d" format specifier? Stick the numbers right in an array, sort it, and write it out.