- public class Solution {
- public boolean
- match(
- char
- [] str,
- char[] pattern) {
- if
- (str ==
- null
- || pattern ==
- null) {
- return false;
- }
- int
- strIndex = 0
- ;
- int
- patternIndex = 0
- ;
- return matchCore(str, strIndex, pattern, patternIndex);
- }
- public boolean
- matchCore(
- char
- [] str,
- int
- strIndex,
- char
- [] pattern,
- int patternIndex) {
- //有效性检验:str到尾,pattern到尾,匹配成功
- if
- (strIndex == str.length && patternIndex ==
- pattern.length) {
- return true;
- }
- //pattern先到尾,匹配失败
- if
- (strIndex != str.length && patternIndex ==
- pattern.length) {
- return false;
- }
- //模式第2个是*,且字符串第1个跟模式第1个匹配,分3种匹配模式;如不匹配,模式后移2位
- if
- (patternIndex + 1 < pattern.length && pattern[patternIndex + 1] == '*'
- ) {
- if
- ((strIndex != str.length && pattern[patternIndex] == str[strIndex]) || (pattern[patternIndex] == '.' && strIndex !=
- str.length)) {
- return
- matchCore(str, strIndex, pattern, patternIndex + 2)
- //模式后移2,视为x*匹配0个字符
- || matchCore(str, strIndex + 1, pattern, patternIndex + 2)
- //视为模式匹配1个字符
- || matchCore(str, strIndex + 1, pattern, patternIndex);
- //*匹配1个,再匹配str中的下一个
- }
- else {
- return
- matchCore(str, strIndex, pattern, patternIndex + 2
- );
- }
- }
- //模式第2个不是*,且字符串第1个跟模式第1个匹配,则都后移1位,否则直接返回false
- if
- ((strIndex != str.length && pattern[patternIndex] == str[strIndex]) || (pattern[patternIndex] == '.' && strIndex !=
- str.length)) {
- return
- matchCore(str, strIndex + 1, pattern, patternIndex + 1
- );
- }
- return false;
- }
- }
来源: http://www.bubuko.com/infodetail-2217553.html