Wrong output in java

Question

(Closed.) This question needs debugging details. It is not currently accepting answers. question from:https://stackoverflow.com/questions/66057415/wrong-output-in-java

Answer 1

Your code works fine only with 3 digit Amstrong numbers:

sum += (int) Math.pow((num % 10), 3);

You could avoid hardcoding this value by checking it at runtime:

public static boolean checkArmstrong(int num) {
    if (num == 0)
        return true; // also avoids log10(0) 
    
    int org = num, sum = 0;
    int digits = (int) (Math.log10(num) + 1);
    
    while (num > 0) { 
       sum += (int) Math.pow((num % 10), digits);
       num /= 10;
    }
   
    return sum == org;
}