Added Solution - GfG to GitHub

Author: DLSireesha

Hard/Possible Paths in a Tree/possible-paths-in-a-tree.cpp

@@ -0,0 +1,114 @@
+//{ Driver Code Starts
+//Initial template for C++
+
+#include <bits/stdc++.h>
+using namespace std;
+
+// } Driver Code Ends
+//User function template for C++
+class Solution {
+int ans;
+private:
+int root(int i, vector<int> &parent)
+{
+    while(parent[i]!=i)
+   {
+       parent[i] = parent[parent[i]];
+       i = parent[i];
+   }
+   return i;
+}
+   int Union(int a, int b, vector<int> &parent, vector<int> &sz)
+   {
+       int ra = root(a, parent);
+       int rb = root(b, parent);
+       if(ra == rb)
+           return sz[ra]*sz[ra];
+       if(sz[ra] < sz[rb])
+   {
+       swap(ra,rb);
+       swap(a,b);
+   }
+       ans += sz[ra]*sz[rb];
+   parent[rb] = ra;
+   sz[ra] += sz[rb];
+   return ans;
+      }
+ public:
+ vector<int> maximumWeight(int n, vector<vector<int>> edges, int q, vector<int> &queries)
+ {
+     ans = 0;
+vector<int> parent(n+1, 0), sz(n+1, 0);
+for(int i = 0;i <= n; i++)
+{
+           parent[i] = i;
+           sz[i] = 1;
+       }
+       vector<pair<int, pair<int, int>>> wt;
+      for(int i = 0; i < n-1; i++)
+            wt.push_back({edges[i][2] , {edges[i][0], edges[i][1]}}); sort(wt.begin() , wt.end());
+       map<int, int> mp;
+       for(int i = 0;i < n-1; i++){
+           int a = wt[i].first;
+           int b = wt[i].second.first;
+           int c = wt[i].second.second;
+           mp[a] = Union(b, c, parent, sz);
+         }
+       vector<int> res;
+       for(int i = 0; i < q; i++)
+       {
+          auto val = mp.upper_bound(queries[i]);
+           if(val == mp.begin())
+               res.push_back(0);
+           else
+            {
+                val--;
+               res.push_back(val->second);
+           }
+      }
+      return res;
+
+}
+
+};
+
+
+
+//{ Driver Code Starts.
+
+int main() 
+{
+   	int t;
+    cin >> t;
+    while (t--)
+    {
+    	int n;
+        cin >> n;
+        
+        vector<vector<int>> edges(n-1, vector<int> (3, 0));
+
+        for(int i = 0; i < n-1; i++)
+        {
+        	for(int j = 0; j < 3; j++)
+        	{
+        		cin >> edges[i][j];
+        	}
+        }
+
+        int q;
+        cin >> q;
+        vector<int> queries(q);
+        for(int i = 0; i < q; i++)
+        	cin >> queries[i];
+
+    	Solution obj;
+    	vector<int> ans = obj.maximumWeight(n, edges, q, queries);
+
+    	for(auto i:ans)
+    		cout << i << " ";
+    	cout << "\n"; 
+    }
+    return 0;
+}
+
+// } Driver Code Ends