s0131

src/s0131_palindrome_partitioning.cpp

@@ -0,0 +1,40 @@
+#include "s0131_palindrome_partitioning.hpp"
+
+bool isPalindrome(const string &s, int begin, int end) {
+  for (int i = begin, j = end; i <= j; ++i, --j) {
+    if (s[i] != s[j]) return false;
+  }
+  return true;
+}
+
+/**
+ * @brief 回溯
+ *
+ * @param path 每个元素都是一个回文串
+ * @param result 存放最终结果
+ * @param s 待处理的字符串
+ * @param startIndex s[0...startIndex - 1] 被分成了很多个子字符串，存放在 path 中
+ */
+void partitionDFS(vector<string> &path, vector<vector<string>> &result, const string &s, int startIndex) {
+  int len = s.length();
+  // 终止条件
+  if (startIndex == len) {
+    result.push_back(path);
+  }
+
+  for (int i = startIndex; i < len; ++i) {
+    // 如果 s[startIndex...i] 是回文串，则进入下一层
+    if (isPalindrome(s, startIndex, i)) {
+      path.push_back(s.substr(startIndex, i - startIndex + 1));
+      partitionDFS(path, result, s, i + 1);
+      path.pop_back();
+    }
+  }
+}
+
+vector<vector<string>> S0131::partition(string s) {
+  vector<vector<string>> result{};
+  vector<string> path{};
+  partitionDFS(path, result, s, 0);
+  return result;
+}