[LintCode] 正则表达式匹配

 1 class Solution {
 2 public:
 3     /**
 4      * @param s: A string 
 5      * @param p: A string includes "." and "*"
 6      * @return: A boolean
 7      */
 8     bool isMatch(const char *s, const char *p) {
 9         // write your code here
10         int m = strlen(s), n = strlen(p);
11         vector<vector<bool> > dp(m + 1, vector<bool> (n + 1, false));
12         dp[0][0] = true;
13         for (int j = 1; j <= n; j++)
14             dp[0][j] = (j > 1 && p[j - 1] == '*' && dp[0][j - 2]);
15         for (int j = 1; j <= n; j++) {
16             for (int i = 1; i <= m; i++) {
17                 if (j > 1 && p[j - 1] == '*') 
18                     dp[i][j] = dp[i][j - 2] || ((s[i - 1] == p[j - 2] || p[j - 2] == '.') && dp[i - 1][j]);
19                 else dp[i][j] = dp[i - 1][j - 1] && (s[i - 1] == p[j - 1] || p[j - 1] == '.');
20             }
21         }
22         return dp[m][n];
23     }
24 };