[10] 正则表达式匹配

src/leecode/10.正则表达式匹配.java

@@ -0,0 +1,50 @@
+package leecode;
+
+/*
+ * @lc app=leetcode.cn id=10 lang=java
+ *
+ * [10] 正则表达式匹配
+ */
+
+import java.util.Stack;
+
+// @lc code=start
+class Solution {
+    public boolean isMatch(String s, String p) {
+        int m = s.length();
+        int n = p.length();
+        boolean[][] dp = new boolean[m + 1][n + 1];
+        dp[0][0] = true;
+        for (int i = 0; i <= m; i++) {
+            for (int j = 1; j <= n; j++) {
+                if (p.charAt(j - 1) == '*') {
+                    dp[i][j] = dp[i][j - 2];
+                    if (match(s, p, i, j - 1)) {
+                        dp[i][j] = dp[i][j] || dp[i - 1][j];
+                    }
+                } else {
+                    if (match(s, p, i, j)) {
+                        dp[i][j] = dp[i - 1][j - 1];
+                    }
+                }
+            }
+        }
+        return dp[m][n];
+    }
+
+    boolean match(String s, String p, int i, int j) {
+        if (i == 0) return false;
+        if (p.charAt(j - 1) == '.') {
+            return true;
+        }
+        return s.charAt(i - 1) == p.charAt(j - 1);
+    }
+
+    public static void main(String[] args) {
+        Solution solution = new Solution();
+        solution.isMatch("aa", "a");
+    }
+
+}
+// @lc code=end
+