Given two strings S and T, determine if they are both one edit distance apart

题目：

i. Modify operation – Modify a character to X in S.
S = “abcde”
T = “abXde”

ii. Insert operation – X was inserted before a character in S.
S = “abcde”
T = “abcXde”

iii. Append operation – X was appended at the end of S.
S = “abcde”
T = “abcdeX”

解答：

 1 public class Solution {
 2 
 3     public static void main(String[] args) {
 4         String s = "abcde";
 5         String t = "abcdeX";
 6 
 7         System.out.println(isOneEditDistance(s, t));
 8     }
 9 
10     public boolean isOneEditDistance(String s, String t) {
11         int m = s.length();
12         int n = t.length();
13         if(m > n) {
14             return isOneEditDistance(t, s);
15         }
16 
17         if(n - m > 1) {
18             return flase;
19         }
20 
21         int i = 0;
22         shift = n - m;
23         while(i < m && s.charAt(i) == t.charAt(i)) {
24             i++;
25         }
26 
27         if(i == m) {
28             return shift > 0;
29         }
30 
31         if(shift == 0) {
32             i++;
33         }
34 
35         while(i < m && s.charAt(i) == t.charAt(i+shift)) {
36             i++;
37         }
38 
39         return i == m;
40     }
41 
42 }