Done a DFS problem in LeetCode Daily Challenge.

Author: zh-plus

LeetCode/daily_challenge/CMakeLists.txt

@@ -1 +1 @@
-add_executable(daily_challenge p2021_3_18_WiggleSubsequence.cpp)
+add_executable(daily_challenge p2021_3_19_KeysAndRooms.cpp)

LeetCode/daily_challenge/p2021_3_19_KeysAndRooms.cpp

@@ -0,0 +1,60 @@
+//
+// Created by 10578 on 2021/3/19.
+//
+
+#include "iostream"
+#include "fstream"
+#include "sstream"
+#include "string"
+#include "iterator"
+#include "algorithm"
+#include "vector"
+#include "unordered_set"
+#include "stack"
+
+#define ALTER_IN(filename) std::fstream fs(filename); std::cin.rdbuf(fs.rdbuf());
+#define BOOST_IO std::ios_base::sync_with_stdio(false); std::cin.tie(nullptr); std::cout.tie(nullptr);
+
+__attribute__((constructor))
+void my_startup(){
+    BOOST_IO;
+}
+
+using namespace std;
+
+class Solution {
+public:
+    bool canVisitAllRooms(vector<vector<int>>& rooms) {
+        unordered_set<int> accessed;
+
+        stack<int> s;
+        s.push(0);
+        accessed.insert(0);
+
+        int current;
+
+        while (!s.empty()) {
+            current = s.top();
+            s.pop();
+
+            for (auto &&x: rooms[current]) {
+                if (!accessed.count(x)) {
+                    s.push(x);
+                    accessed.insert(x);
+
+                    if (accessed.size() == rooms.size()) {
+                        return true;
+                    }
+                }
+            }
+        }
+
+        return accessed.size() == rooms.size();
+    }
+};
+
+int main(){
+
+
+    return 0;
+}