public class Solution {
public boolean isStrobogrammatic(String num) {
if(num == null || num.length() == 0) return true;
HashMap<Character, Character> map = new HashMap<Character, Character>();
map.put('0', '0');
map.put('1', '1');
map.put('8', '8');
map.put('6', '9');
map.put('9', '6');
int start = 0;
int end = num.length() - 1;
while(start <= end) {
char temp1 = num.charAt(start);
char temp2 = num.charAt(end);
if(map.containsKey(temp1) && map.get(temp1) == temp2) {
start++;
end--;
continue;
}
return false;
}
return true;
}
}