Given two strings S and T, determine if they are both one edit distance apart.
Solution：String
思路：
Time Complexity: O(N) Space Complexity: O(1)
Solution Code：
class Solution {
/*
* There're 3 possibilities to satisfy one edit distance apart:
*
* 1) Replace 1 char:
s: a B c
t: a D c
* 2) Delete 1 char from s:
s: a D b c
t: a b c
* 3) Delete 1 char from t
s: a b c
t: a D b c
*/
public boolean isOneEditDistance(String s, String t) {
for (int i = 0; i < Math.min(s.length(), t.length()); i++) {
if (s.charAt(i) != t.charAt(i)) {
if (s.length() == t.length()) // s has the same length as t, so the only possibility is replacing one char in s and t
return s.substring(i + 1).equals(t.substring(i + 1));
else if (s.length() < t.length()) // t is longer than s, so the only possibility is deleting one char from t
return s.substring(i).equals(t.substring(i + 1));
else // s is longer than t, so the only possibility is deleting one char from s
return t.substring(i).equals(s.substring(i + 1));
}
}
//All previous chars are the same, the only possibility is deleting the end char in the longer one of s and t
return Math.abs(s.length() - t.length()) == 1;
}
}
