C/C++ Identify the digits in a given number.

Question

Hello everyone, i'm new to programming.. and i'm stuck at a problem.. I want my program to identify the separate digits in a given number, like if i input 4692, it should identify the digits and print 4 6 9 2. And yeah, without using arrays.. Thanks in advance!

Answer 1

A perfect recursion problem to tackle if you're new to programming...

4692/1000 = 4

4692%1000 = 692

692/100 = 6

692%100 = 92

92/10 = 9

92%10 = 2

You should get the idea for the loop you should use now, so that it works for any number. :)

Answer 2

Haven't written C code in year, but this should work.

int i = 12345;

while( i > 0 ){
   int nextVal = i % 10;
   printf( "%d", nextVal );
   i = i / 10;
}

Answer 3

Here is a simple solution if you want to just print the digits from the number.

#include 
/**
 printdigits
*/
void printDigits(int num) {

  char buff[128] = "";
  sprintf(buff, "%d ", num);
  int i = 0;
  while (buff[i] != '\0') {
     printf("%c ", buff[i]);
     i++;
   }
  printf("\n");
}
/*
 main function
*/
int main(int argc, char** argv) {
   int digits = 4321;
   printDigits(digits);
   return 0;
}

Answer 4

I think the idea is to have non reapeating digits printed (otherwise it would be too simple)... well, you can keep track of the already printed integers without having an array encoding them in another integer.

some pseudo C, to give you a clue:

int encoding = 0;
int d;

while (keep_looking()) {
  d = get_digit();
  if (encoding/(2**d)%2 == 0) {
    print(d);
    encoding += 2**d;
  }
}