10、正则表达式

class Solution{
        public boolean isMatch(String s,String p){
            char[] sCharArray = s.toCharArray();
            char[] pCharArray = p.toCharArray();
            //初始化dp表
            int[][] dp = new int[pCharArray.length+1][sCharArray.length+1];
            for(int i = 0;i <sCharArray.length+1;i++){
                dp[pCharArray.length][i] = 2; //false
            }
            dp[pCharArray.length][sCharArray.length] = 1;//true

            //填表
            boolean flagStar = false; //记录*号
            int matchedIndex = sCharArray.length;
            for(int i = pCharArray.length-1; i>-1;i--){
                if(pCharArray[i] == '*'){
                    flagStar = true;
                    for(int k = 0;k < matchedIndex+1;k++){
                        dp[i][k] = dp[i+1][k];
                    }
                    continue;
                }
                if(flagStar){
                    boolean flagNextMatched = false;
                    for(int j = matchedIndex; j > -1;j--){
                        if(flagNextMatched == true){
                            if(pCharArray[i] == '.'){
                                dp[i][j] = 1;
                            }else if(pCharArray[i] == sCharArray[j]){
                                dp[i][j] = 1;
                            }else{
                                if(dp[i+1][j] == 1){
                                    flagNextMatched = true;
                                    dp[i][j] = 1;
                                }else{
                                    flagNextMatched = false;
                                    dp[i][j] = 2;
                                }
                            }
                        }else{
                            if(dp[i+1][j] == 1){
                                flagNextMatched = true;
                                dp[i][j] = 1;
                            }else{
                                flagNextMatched = false;
                                dp[i][j] = 2;
                            }
                        }
                    }
                }else{
                    matchedIndex--;
                    for(int j = matchedIndex; j > -1; j--){
                        if(dp[i+1][j+1] == 1 &&(pCharArray[i]=='.' || pCharArray[i] == sCharArray[j]) ){
                            dp[i][j] = 1;
                        }else{
                            dp[i][j] = 2;
                        }
                    }
                }
                flagStar = false;

            }
            return dp[0][0] == 1 ? true : false;
        }
    }