Plus One

public int[] plusOne(int[] digits) {
// Start typing your Java solution below
// DO NOT write main() function
int len = digits.length - 1;
int flag = 1;

do{
int temp = digits[len] + flag;
if(temp == 10){
digits[len] = 0;
flag = 1;
}else{
digits[len] = temp;
flag = 0;
}
len--;
}while(flag == 1 && len >= 0);

if(flag == 0){
return digits;
}else{
int[] dig = new int[digits.length + 1];
dig[0] = 1;
for(int i = 0; i < digits.length; i ++){
dig[i + 1] = 0;
}
return dig;
}
}