examples

#include <stdio.h>

int main(int argc, char* argv[]) {
  int n, c, k, space = 1;

  FILE *ptr_file;
  char buf[1000];

  ptr_file =fopen(argv[1], "r");
  if (!ptr_file)
      return 1;

  fgets(buf, 1000, ptr_file);
  n = atoi(buf);

  fclose(ptr_file);

  space = n - 1;

  for (k = 1; k <= n; k++)
  {
    for (c = 1; c <= space; c++)
      printf(" ");

    space--;

    for (c = 1; c <= 2*k-1; c++)
      printf("*");

    printf("\n");
  }

  space = 1;

  for (k = 1; k <= n - 1; k++)
  {
    for (c = 1; c <= space; c++)
      printf(" ");

    space++;

    for (c = 1 ; c <= 2*(n-k)-1; c++)
      printf("*");

    printf("\n");
  }

  return 0;
}



// SORT STRING
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

void sort_string(char*);

int main(int argc, char* argv[]) {
   char string[100];

   FILE *ptr_file;

    ptr_file =fopen(argv[1], "r");
    if (!ptr_file)
        return 1;

    fgets(string, 100, ptr_file);

    fclose(ptr_file);

    sort_string(string);
    printf("%s\n", string);

    return 0;
}

void sort_string(char *s) {
    int c, d = 0, length;
    char *pointer, *result, ch;

    length = strlen(s);

    result = (char*)malloc(length+1);

    pointer = s;

    for ( ch = 'a' ; ch <= 'z' ; ch++ ) {
        for ( c = 0 ; c < length ; c++ ) {
            if ( *pointer == ch ) {
                *(result+d) = *pointer;
                d++;
            }
            pointer++;
        }
        pointer = s;
    }
    *(result+d) = '\0';

    strcpy(s, result);
    free(result);
}


// ODD OR EVEN
#include<stdio.h>

int main(int argc, char* argv[]) {
    int n;

    FILE *ptr_file;
    char buf[1000];

    ptr_file =fopen(argv[1], "r");
    if (!ptr_file)
        return 1;

    fgets(buf, 1000, ptr_file);
    n = atoi(buf);

    fclose(ptr_file);


   if ( n%2 == 0 )
      printf("Even\n");
   else
      printf("Odd\n");

  return 0;
}