weak pointer added

Author: ArbitCode

CPP/Modern-cpp.md

@@ -1,2 +1,32 @@
 [awesome cpp](https://github.com/rigtorp/awesome-modern-cpp)<br>
 [Modern c++](https://www.modernescpp.com/index.php/table-of-content/)
+
+- Memory Model
+  1. Overview
+  2. Atomic data types
+    1. std::atomic_flag
+    2. std::atomic
+    3. std::atomic
+  3. Synchronization and ordering constraints
+  4. Diff C++ memory model
+    1. Sequential consistency
+    2. Acquire-release semantic
+  5. Fences
+  6. Algorithms
+- Threading interface
+  1. Threads
+  2. Thread local data
+  3. Condition Variable
+  4. Tasks
+- Multithreading with C++17 and C++20
+  1. Parallel Algorithms of STL
+  2. Atomic Smart Pointers
+  3. std::future extensions
+  4. Latches and Barriers
+  5. Coroutines
+  6. Transactional Memory
+  7. Task Blocks
+  8. Executors
+  9. Unified Future
+  10. std::jthread
+- Application of Multithreading

DSA/Graph/GraphInput.cpp

@@ -0,0 +1,43 @@
+#include <iostream>
+#include <vector>
+#include<queue>
+using namespace std;
+
+void BFSRecursive(const vector<vector<pair<int, int>>> &graph, queue<int> &q,
+                  vector<bool> &discovered) {
+  if (q.empty())
+    return;
+  int v = q.front();
+  q.pop();
+  cout << v << " ";
+  for(auto u : graph[v]) {
+    if (!discovered[u.first])
+      discovered[u.first] = true;
+    q.push(u.first);
+  }
+  BFSRecursive(graph, q, discovered);
+}
+int main()
+{
+    int n, m;
+    cin >> n >> m;
+    vector<vector<pair<int, int> > > graph(n, vector<pair<int, int> >(m));
+    // undirected graph
+    for (int i = 0; i < m; i++)
+    {
+        int u, v, w;
+        cin >> u >> v >> w;
+        graph[u].push_back(make_pair(v, w));
+        graph[v].push_back(make_pair(u, w));
+    }
+    // directed graph
+    for (int i = 0; i < m; i++)
+    {
+        int u, v, w;
+        cin >> u >> v >> w;
+        graph[u].push_back(make_pair(v, w));
+    }
+    queue<int> q;
+    vector<bool> discovered;
+    BFSRecursive(graph, q, discovered);
+}