This Program allow user to convert an integer in decimal value into base 2, 8, 16

Decimalconverter.c

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

long decimalToBinary( long integerInDecimal);
long decimalToOctal( long integerInDecimal);
void decimalToHexadecimal( long integerInDecimal);
int main() {
    long integerInDecimal;
    char option = 'y';
    // Display information
    printf("===============================================================================\n");
    printf("This Program allow user to convert an integer in decimal value into base 2, 8 , 16\n");
    printf("Author Name: Khem Puthea\n");
    printf("===============================================================================\n");
    /* check condition to restart or quit */
    while (option == 'y') {
        printf("Enter a decimal number: ");
        scanf("%ld", &integerInDecimal);
        printf("Octal number of %ld is %ld\n", integerInDecimal, decimalToOctal(integerInDecimal));
        printf("Binary number of %ld is %ld\n", integerInDecimal, decimalToBinary(integerInDecimal));

        /* Directly call function convert decimal to hexadecimal*/
        printf("Hexdecimal number of %ld is ", integerInDecimal);
        decimalToHexadecimal(integerInDecimal);
        /* ask user to choose option restart or quit*/
        printf("\nDo you want to continue: (y/n) ");
        scanf("%s", &option);
        printf("----------------------------------------------------------\n");
    }
    printf("Thank you for using this conversion application\n");
    printf("=================================================");
    return 0;
}


/* Function to convert a decinal number to octal number */
long decimalToOctal(long integerInDecimal) {
    int remainder;
 long octal = 0, i = 1;

    while(integerInDecimal != 0) {
        remainder = integerInDecimal%8;
        integerInDecimal = integerInDecimal/8;
        octal = octal + (remainder*i);
        i = i*10;
    }
    return octal;
}

/* Function to convert a decinal number to binary number */
long decimalToBinary(long integerInDecimal) {
    int remainder;
 long binary = 0, i = 1;

    while(integerInDecimal != 0) {
        remainder = integerInDecimal%2;
        integerInDecimal = integerInDecimal/2;
        binary= binary + (remainder*i);
        i = i*10;
    }
    return binary;
}


/* Function to convert a decimal number to Hexadecimal*/
void decimalToHexadecimal( long integerInDecimal) {
long int remainder[50],i=0,length=0;

while(integerInDecimal>0) {
      remainder[i]= integerInDecimal%16;
      integerInDecimal = integerInDecimal/16;
      i++;
      length++;
   }

printf(" : ");
    for(i=length-1;i>=0;i--) {
        switch(remainder[i])
        {
          case 10:
              printf("A");
              break;
          case 11:
              printf("B");
              break;
          case 12:
              printf("C");
              break;
          case 13:
              printf("D");
              break;
          case 14:
              printf("E");
              break;
          case 15:
              printf("F");
              break;
          default :
             printf("%ld",remainder[i]);
        }
      }
}