Added iterpolationSearch and dfs in C++ (Phantsure#6)

Author: PrakharUniyal

Searching/c++/interpolationSearch.cpp

@@ -0,0 +1,42 @@
+#include<bits/stdc++.h> 
+using namespace std;
+string interpolationSearch(vector<int> a, int l, int r, int num)
+{
+ r--; 
+ while (l <= r && num >= a[l] && num <= a[r])
+ {
+ // Probing the position with keeping 
+ // uniform distribution in mind.
+ int pos = l + (((double)(r - l) / (a[r] - a[l])) * (num - a[l]));
+
+ // Condition of target found
+ if (a[pos] == num) return("Found");
+
+ // If x is larger, x is in upper part
+ if (a[pos] < num) l = pos + 1;
+
+ // If x is smaller, x is in the lower part
+ else r = pos - 1;
+ }
+ return("Not Found");
+}
+
+int main()
+{
+ int n;
+ cout << "Enter total number of elements: ";
+ cin >> n;
+ cout << "Enter Elements";
+ int i = n;
+ vector<int> a;
+ while (i--)
+ {
+ int t;
+ cin >> t;
+ a.push_back(t);
+ }
+ int num;
+ cout << "enter number to search";
+ cin >> num;
+ cout << interpolationSearch(a, 0, n, num);
+}

graph/c++/dfs.cpp

@@ -0,0 +1,86 @@
+#include<iostream>
+#include <list>
+
+using namespace std;
+
+// This class represents a directed graph using
+// adjacency list representation
+class Graph
+{
+ int V; // No. of vertices
+
+ // Pointer to an array containing adjacency
+ // lists
+ list<int> *adj;
+
+ // A recursive function used by DFS
+ void DFSUtil(int s, bool visited[]);
+
+public:
+ Graph(int V); // Constructor
+
+ // function to add an edge to graph
+ void addEdge(int v, int w);
+
+ // prints DFS traversal from a given source s
+ void DFS(int s);
+};
+
+Graph::Graph(int V)
+{
+ this->V = V;
+ adj = new list<int>[V];
+}
+
+void Graph::addEdge(int v, int w)
+{
+ adj[v].push_back(w); // Add w to v’s list.
+}
+
+void Graph::DFSUtil(int s, bool visited[])
+{
+ // Mark the current node as visited and
+ // print it
+ visited[s] = true;
+ cout << s << " ";
+
+ // Recur for all the vertices adjacent
+ // to this vertex
+ list<int>::iterator i;
+ for (i = adj[s].begin(); i != adj[s].end(); ++i)
+ if (!visited[*i])
+ DFSUtil(*i, visited);
+}
+
+// DFS traversal of the vertices reachable from s.
+// It uses recursive DFSUtil()
+void Graph::DFS(int s)
+{
+ // Mark all the vertices as not visited
+ bool *visited = new bool[V];
+ for (int i = 0; i < V; i++)
+ visited[i] = false;
+
+ // Call the recursive helper function
+ // to print DFS traversal
+ DFSUtil(s, visited);
+}
+
+// Driver program to test methods of graph class
+int main()
+{
+ // Create a graph given in the above diagram
+ Graph g(4);
+ g.addEdge(0, 1);
+ g.addEdge(0, 2);
+ g.addEdge(1, 2);
+ g.addEdge(2, 0);
+ g.addEdge(2, 3);
+ g.addEdge(3, 3);
+
+ cout << "Following is Depth First Traversal"
+ " (starting from vertex 2) \n";
+ g.DFS(2);
+
+ return 0;
+}