[leetcode]Strobogrammatic Number

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public class Solution { boolean rightMapping(char c1, char c2){ if (c1 > c2) return rightMapping(c2,c1); if (c1 == '0') return c2 == '0'; if (c1 == '1') return c2 == '1'; if (c1 == '6') return c2 == '9'; if (c1 == '8') return c2 == '8'; return false; } public boolean isStrobogrammatic(String num) { char[] arr = num.toCharArray(); int left = 0; int right = arr.length-1; while (left <= right){ if (!rightMapping(arr[left++], arr[right--])) return false; } return true; } }