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Swap first and last digits of a number

eg . 1234 4231

28th Jun 2019, 7:02 AM
Manindra Shah
Manindra Shah - avatar
2 Respostas
+ 1
if you have int 1234 converted to String "1234", it is easy swap first and last character and convert "4231" to int if you need math. solution of length int length = (int) (Math.log10(n)+1); or you can divide with 10 in loop for first, (int) conversion is necessary int y = n / (int) Math.pow(10, length-1);
28th Jun 2019, 10:20 PM
zemiak
0
Integer.toString gives you the length of your number. n % 10 -> last digit n / 10^length - 1 -> first digit In your case: length = 4; int first = 1; int last = 4; n -= first * (10^length-1); //1234 - 1000 = 234 n += last * (10^length-1); //234 + 4000 = 4234 n -= last; //4234 - 4 = 4230 n += first; //4230 + 1 = 4231 10^... -> you can use Math.pow(10, length - 1);
28th Jun 2019, 1:34 PM
Denise Roßberg
Denise Roßberg - avatar