161 相隔为1的编辑距离

  1. class Solution {
  2.     public boolean isOneEditDistance(String first, String second) {
  3.         if (first == null && second == null)
  4.             return true;
  6.         if (first.equals(second))
  7.             return false;
  9.         // 两个字符串的长度相等时逐个进行判断
  10.         if (first.length() == second.length()) {
  11.             int diff = 0;
  12.             for (int i = 0; i < first.length(); ++i) {
  13.                 if (first.charAt(i) != second.charAt(i))
  14.                     ++diff;
  16.                 if (diff >= 2)
  17.                     return false;
  18.             }
  20.             return true;
  21.         } // if
  23.         // 两个字符串的长度相差1时，碰到不相等位置长串指针后移2步
  24.         else if (Math.abs(first.length() - second.length()) == 1) {
  25.             int i = 0, j = 0;
  26.             int diff = 0;
  28.             while (i < first.length() && j < second.length()) {
  29.                 if (first.charAt(i) != second.charAt(j)) {
  30.                     ++diff;
  31.                     if (diff >= 2)
  32.                         return false;
  34.                     if (first.length() > second.length())
  35.                         ++i;
  36.                     else 
  37.                         ++j;
  38.                 }
  39.                 else if (first.charAt(i) == second.charAt(j)) {
  40.                     ++i; 
  41.                     ++j;
  42.                 }
  43.             } // while
  45.             return true;
  46.         } 
  48.         return false;
  49.     }
  50. }