s0010

include/s0010_regular_expression_matching.hpp

@@ -0,0 +1,14 @@
+#ifndef S0010_REGULAR_EXPRESSION_MATCHING
+#define S0010_REGULAR_EXPRESSION_MATCHING
+
+#include <string>
+#include <vector>
+
+using namespace std;
+
+class Solution {
+ public:
+  bool isMatch(string s, string p);
+};
+
+#endif

src/s0010_regular_expression_matching.cpp

@@ -0,0 +1,37 @@
+#include "s0010_regular_expression_matching.hpp"
+
+// 动态规划
+// 当前匹配成功 == 之前匹配成功 && 当前字符匹配成功
+
+bool Solution::isMatch(string s, string p) {
+  int m = s.size();
+  int n = p.size();
+
+  auto matches = [&](int i, int j) {
+    if (i == 0) {
+      return false;
+    }
+    if (p[j - 1] == '.') {
+      return true;
+    }
+    return s[i - 1] == p[j - 1];
+  };
+
+  vector<vector<int>> f(m + 1, vector<int>(n + 1));
+  f[0][0] = true;
+  for (int i = 0; i <= m; ++i) {
+    for (int j = 1; j <= n; ++j) {
+      if (p[j - 1] == '*') {
+        f[i][j] |= f[i][j - 2];
+        if (matches(i, j - 1)) {
+          f[i][j] |= f[i - 1][j];
+        }
+      } else {
+        if (matches(i, j)) {
+          f[i][j] |= f[i - 1][j - 1];
+        }
+      }
+    }
+  }
+  return f[m][n];
+}

tests/s0010_regular_expression_matching.cpp

@@ -0,0 +1,24 @@
+#include "s0010_regular_expression_matching.hpp"
+
+#include <gtest/gtest.h>
+
+TEST(Problem10, Case1) {
+  string s{"aa"};
+  string p{"a"};
+  Solution solution;
+  EXPECT_FALSE(solution.isMatch(s, p));
+}
+
+TEST(Problem10, Case2) {
+  string s{"aa"};
+  string p{"a*"};
+  Solution solution;
+  EXPECT_TRUE(solution.isMatch(s, p));
+}
+
+TEST(Problem10, Case3) {
+  string s{"ab"};
+  string p{".*"};
+  Solution solution;
+  EXPECT_TRUE(solution.isMatch(s, p));
+}