leetcode-----10. 正则表达式匹配

• 链接：https://leetcode-cn.com/problems/regular-expression-matching/

代码

class Solution {
    public boolean isMatch(String s, String p) {
        int sl = s.length();
        int pl = p.length();
        boolean[][] dp = new boolean[sl + 1][pl + 1];
        dp[0][0] = true;

        for (int j = 2; j <= pl; ++j) {
            dp[0][j] = dp[0][j - 2] && p.charAt(j - 1) == '*';
        }

        for (int i = 1; i <= sl; ++i) {
            for (int j = 1; j <= pl; ++j) {
                int m = i - 1, n = j - 1;
                if (p.charAt(n) == '*') {
                    dp[i][j] = dp[i][j - 2] || dp[i - 1][j] && (s.charAt(m) == p.charAt(n - 1) || p.charAt(n - 1) == '.');
                } else if (s.charAt(m) == p.charAt(n) || p.charAt(n) == '.') {
                    dp[i][j] = dp[i - 1][j - 1];
                }
            }
        }
        return dp[sl][pl];
    }
}