C program to generate and print armstrong numbers

#include <stdio.h>
 
int check_armstrong(int);
int power(int, int);
 
int main () {
   int c, a, b;
 
   printf("Input two integers\n");
   scanf("%d%d", &a, &b);
 
   for (c = a; c <= b; c++) {
      if (check_armstrong(c) == 1)
         printf("%d\n", c);
   }
 
   return 0;
}
 
int check_armstrong(int n) {
   long long sum = 0, temp;
   int remainder, digits = 0;
 
   temp = n;
 
   while (temp != 0) {
      digits++;
      temp = temp/10;
   }
 
   temp = n;
 
   while (temp != 0) {
      remainder = temp%10;
      sum = sum + power(remainder, digits);
      temp = temp/10;
   }
 
   if (n == sum)
      return 1;
   else
      return 0;
}
 
int  power(int n, int r) {
   int c, p = 1;
 
   for (c = 1; c <= r; c++) 
      p = p*n;
 
   return p;   
}

Output:

Input two integers

100 400

153

370

371