Merge pull request #20 from knockcat/patch-1

Create Get_Path_DFS.cpp

Author: Mehulcoder

Graphs1/Get_Path_DFS.cpp

@@ -0,0 +1,131 @@
+// Get Path DFS
+
+#include <iostream>
+#include <vector>
+using namespace std;
+
+vector<int> Get_Path(int **edges, int n, int s, int d, bool *visited)
+{
+    if (s == d)
+    {
+        vector<int> ans;
+        visited[s] = true;
+        ans.push_back(s);
+        return ans;
+    }
+
+    visited[s] = true;
+
+    for (int i = 0; i < n; ++i)
+    {
+        if (edges[s][i] == 1 && !visited[i])
+        {
+            vector<int> ans = Get_Path(edges, n, i, d, visited);
+
+            if (!ans.empty())
+            {
+                ans.push_back(s);
+                return ans;
+            }
+        }
+    }
+
+    return {};
+}
+
+int main()
+{
+    // KNOCKCAT \\
+
+    int n, e;
+    cout << "Enter number of vertices & edges : " << endl;
+    cin >> n >> e;
+
+    // for storing we need a 2d arary n*n;
+    int **edges = new int *[n];
+
+    for (int i = 0; i < n; ++i)
+    {
+        edges[i] = new int[n];
+        for (int j = 0; j < n; ++j)
+            edges[i][j] = 0;
+    }
+
+    for (int i = 0; i < e; ++i) // e edges
+    {
+        int f, s; // first vertex second vertes
+        cout << "Enter edge from first vertex to second vertex" << endl;
+
+        cin >> f >> s;
+        edges[f][s] = 1;
+        edges[s][f] = 1;
+    }
+
+    bool *visited = new bool[n];
+
+    for (int i = 0; i < n; ++i)
+        visited[i] = false;
+
+    int s, d;
+    vector<int> ans;
+    cout << "Enter source vertex & destination vertex for path " << endl;
+    cin >> s >> d;
+
+    ans = Get_Path(edges, n, s, d, visited);
+
+    cout << "Path from " << s << " to " << d << endl;
+
+    if (!ans.empty())
+    {
+        for (auto i : ans)
+            cout << i << " ";
+    }
+    else
+        cout << "No Path" << endl;
+
+    // deleting memory
+    for (int i = 0; i < n; ++i)
+        delete[] edges[i];
+
+    delete[] edges;
+
+    delete[] visited;
+
+    return 0;
+}
+
+/*
+
+OUTPUT
+
+PS E:\DOCUMENTS\C-Plus-Plus-Programming\Graph> cd "e:\DOCUMENTS\C-Plus-Plus-Programming\Graph\" ; if ($?) { g++ Get_Path_DFS.cpp -o Get_Path_DFS } ; if ($?) { .\Get_Path_DFS }
+Enter number of vertices & edges :
+4 4
+Enter edge from first vertex to second vertex
+0 1
+Enter edge from first vertex to second vertex
+0 3
+Enter edge from first vertex to second vertex
+1 2
+Enter edge from first vertex to second vertex
+2 3
+Enter source vertex & destination vertex for path
+1 3
+Path from 1 to 3
+3 0 1
+PS E:\DOCUMENTS\C-Plus-Plus-Programming\Graph> cd "e:\DOCUMENTS\C-Plus-Plus-Programming\Graph\" ; if ($?) { g++ Get_Path_DFS.cpp -o Get_Path_DFS } ; if ($?) { .\Get_Path_DFS }
+Enter number of vertices & edges :
+6 3
+Enter edge from first vertex to second vertex
+5 3
+Enter edge from first vertex to second vertex
+0 1
+Enter edge from first vertex to second vertex
+3 4
+Enter source vertex & destination vertex for path
+0 3
+Path from 0 to 3
+No Path
+PS E:\DOCUMENTS\C-Plus-Plus-Programming\Graph>
+
+*/