[Leetcode] Add all paths from source to target

Author: GauthamBanasandra

Leetcode/Practice/Medium/797/All paths from source to target.cpp

@@ -0,0 +1,70 @@
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+using Node = int;
+
+class Solution {
+public:
+  vector<vector<int>> allPathsSourceTarget(vector<vector<int>> &graph);
+
+private:
+  void Dfs(Node u, const vector<vector<int>> &graph, vector<int> &path);
+  void InitializeDegrees(const vector<vector<int>> &graph);
+
+  vector<vector<Node>> all_paths_;
+  vector<int> in_degree_;
+  vector<int> out_degree_;
+};
+
+vector<vector<int>> Solution::allPathsSourceTarget(vector<vector<int>> &graph) {
+  InitializeDegrees(graph);
+
+  vector<Node> path;
+  Dfs(0, graph, path);
+
+  return all_paths_;
+}
+
+void Solution::Dfs(Node u, const vector<vector<int>> &graph,
+                   vector<int> &path) {
+  if (u == static_cast<Node>(graph.size()) - 1) {
+    path.emplace_back(u);
+    all_paths_.emplace_back(path);
+    path.pop_back();
+    return;
+  }
+
+  path.emplace_back(u);
+
+  for (const Node v : graph[u]) {
+    Dfs(v, graph, path);
+  }
+
+  path.pop_back();
+}
+
+void Solution::InitializeDegrees(const vector<vector<int>> &graph) {
+  in_degree_.resize(graph.size());
+  out_degree_.resize(graph.size());
+  for (auto u = 0; u < static_cast<Node>(graph.size()); ++u) {
+    for (const Node v : graph[u]) {
+      ++in_degree_[v];
+      ++out_degree_[u];
+    }
+  }
+}
+
+int main(int argc, char *argv[]) {
+  vector<vector<Node>> graph{{4, 3, 1}, {3, 2, 4}, {3}, {4}, {}};
+
+  for (const auto &path : Solution().allPathsSourceTarget(graph)) {
+    for (const auto node : path) {
+      cout << node << ", ";
+    }
+    cout << endl;
+  }
+
+  return 0;
+}

leetcode/CMakeLists.txt

@@ -67,6 +67,7 @@ set(CMAKE_CXX_STANDARD 20)
     add_executable(Sum_of_mutated_array_close_to_target "Practice/Medium/1300/Sum of mutated array close to target.cpp")
     add_executable(Deepest_leaves_sum "Practice/Medium/1302/Deepest leaves sum.cpp")
     add_executable(Number_of_operations_to_make_network_connected "Practice/Medium/1319/Number of operations to make network connected.cpp")
+    add_executable(All_paths_from_source_to_target "Practice/Medium/797/All paths from source to target.cpp")
 
     # Hard
     add_executable(Merge_k_sorted_lists "Practice/Hard/23/Merge k sorted lists.cpp")