Problem
In 1-9 keypad one key is not working. If someone enters a password then not working key will not be entered. You have given expected password and entered password. Check that entered password is valid or not. Ex: entered 164, expected 18684 (you need to take care as when u enter18684 and 164 only both will be taken as 164 input)
Solution
有几种情况需要考虑下，
1. 没有按到过坏的键
2. 1864， 1684. 坏的是8， 坏的键又出现一次
2. expect有可能是186848888，要继续检查直到长度相等
1 public static boolean validPassword(String expect, String actual) { 2 char faultKey = ‘\0‘; //initial fault key 3 int i=0, j=0; //two pointer for each string 4 for(; i<actual.length() && j<expect.length(); j++) { 5 if(actual.charAt(i) != expect.charAt(j)) { 6 if(faultKey == ‘\0‘) faultKey = expect.charAt(j); //record fault key 7 else if(faultKey != expect.charAt(j)) return false; //found second fault key 8 i--; 9 } 10 i++; 11 } 12 13 for(int k=0; k<expect.length() ;k++) { 14 if(faultKey == expect.charAt(k)) return false; 15 } 16 //fault key may require press many times after that 17 while(j<expect.length() && expect.charAt(j)==faultKey) j++; 18 19 return (i==actual.length() && j==expect.length() && faultKey == ‘\0‘) ? true : false; 20 }
原文：http://www.cnblogs.com/superbo/p/4111923.html