path more than k

Author: okmd

backtracking/lb-15-path-more-than-k-length.cpp

@@ -0,0 +1,66 @@
+// from source node to destination node atleat k distance should be there;
+#include<iostream>
+#include<vector>
+using namespace std;
+typedef pair<int, int>edge;
+class Graph {
+    int V;
+    vector<edge>* adj;
+    bool helper(int u, int k, vector<bool>& path) {
+        if (k <= 0) return true;
+        for (auto [v, w] : adj[u]) {
+            if (path[v]) continue; // if current node exits in path i.e hence cycle; so ignore this path;
+            if (w >= k) return true; // if curr edge weight is more than k hence it itself make path more than k hence return true;
+            path[v] = true; // take this node in path
+            if (helper(v, k - w, path)) return true; // remove w from requrired k;
+            path[v] = false; // if including this node not found path hence make it false and try next node;
+        }
+        // if any of the adjacent node of u did not find path >= k hence return false;
+        return false;
+    }
+public:
+
+    Graph(int v) {
+        V = v;
+        adj = new vector<edge>[V];
+    }
+    void addEdge(int u, int v, int w) {
+        adj[u].push_back({ v,w });
+        adj[v].push_back({ u,w });
+    }
+    bool pathMoreThanK(int u, int k) {
+        vector<bool> path(V, false);
+        path[u] = 1;
+        return helper(u, k, path);
+    }
+};
+int main() {
+    // create the graph given in above figure
+    int V = 9;
+    Graph g(V);
+
+    //  making above shown graph
+    g.addEdge(0, 1, 4);
+    g.addEdge(0, 7, 8);
+    g.addEdge(1, 2, 8);
+    g.addEdge(1, 7, 11);
+    g.addEdge(2, 3, 7);
+    g.addEdge(2, 8, 2);
+    g.addEdge(2, 5, 4);
+    g.addEdge(3, 4, 9);
+    g.addEdge(3, 5, 14);
+    g.addEdge(4, 5, 10);
+    g.addEdge(5, 6, 2);
+    g.addEdge(6, 7, 1);
+    g.addEdge(6, 8, 6);
+    g.addEdge(7, 8, 7);
+
+    int src = 0;
+    int k = 62;
+    cout << (g.pathMoreThanK(src, k) ? "Yes\n" : "No\n");
+
+    k = 60;
+    cout << (g.pathMoreThanK(src, k) ? "Yes\n" : "No\n");
+    return 0;
+}
+// https://leetcode.com/playground/LbdfKDz5