Add lcci/0809-bracket/solution.cc

Author: Yestercafe

lcci/0809-bracket/solution.cc

@@ -0,0 +1,34 @@
+class Solution {
+public:
+    vector<string> generateParenthesis(int n) {
+        vector<string> ans;
+
+        function<void(int, int, string&)> dfs = [&](int rem_pa, int in_cnt, string& path) {
+            if (path.length() == n * 2) {
+                cout << path << " " << rem_pa << ' ' << in_cnt << endl;
+                ans.push_back(path);
+                return;
+            }
+            
+            if (rem_pa) {
+                path.push_back('(');
+                dfs(rem_pa - 1, in_cnt + 1, path);
+                path.pop_back();
+            }
+
+            if (in_cnt) {
+                path.push_back(')');
+                dfs(rem_pa, in_cnt - 1, path);
+                path.pop_back();
+            }
+        };
+
+        string path;
+        path.reserve(n * 2);
+
+        dfs(n, 0, path);
+
+        return ans;
+    }
+};
+