Comparator structure added

Author: zarif98sjs

Miscellaneous/01 Operator Overloading for Sorting (Part 1).cpp

@@ -72,7 +72,7 @@ class Node
  }
 };
 
-ostream &operator <<(ostream &os, Node &node)
+ostream &operator <<(ostream &os, const Node &node)
 {
  os<<"Id : "<<node.id<<" , Cost : "<<node.cost<<" , Name : "<<node.name;
  return os;
@@ -86,10 +86,26 @@ bool cmp(const Node &A,const Node &B) /** Sort with descending order of cost **/
  return A.cost>B.cost;
 }
 
+struct Comparator
+{
+ bool operator()(const Node &A,const Node &B) /** Sort with descending order of cost **/
+ {
+ if(A.cost==B.cost)
+ return A.name<B.name;
+
+ return A.cost>B.cost;
+ }
+};
+
+
 int main()
 {
  optimizeIO();
 
+ /**
+ VECTOR
+ **/
+
  vector<Node>v;
 
  v.push_back(Node(1,100,"C"));
@@ -100,10 +116,42 @@ int main()
 
  cout<<v<<endl;
 
- sort(ALL(v),cmp);
+ sort(ALL(v),cmp); /** comparator function **/
+ sort(ALL(v),Comparator()); /** comparator structure **/
 
  cout<<v<<endl;
 
+ /**
+ SET
+ **/
+
+ set<Node,Comparator>st; /** Uses the Comparator structure **/
+ st.insert(Node(1,100,"C"));
+ st.insert(Node(1,100,"A"));
+ st.insert(Node(1,100,"B"));
+ st.insert(Node(1,500,"AB"));
+ st.insert(Node(1,50,"ABC"));
+
+ for(auto x:st)
+ cout<<x.cost<<" "<<x.name<<endl;
+
+ /**
+ Priority Queue
+ PRIORITY QUEUE is MAX HEAP by default .
+ So , the result will be opposite of what we got in SET .
+ **/
+
+ priority_queue<Node,vector<Node>,Comparator>pq;
+ pq.push(Node(1,100,"C"));
+ pq.push(Node(1,100,"A"));
+ pq.push(Node(1,100,"B"));
+ pq.push(Node(1,500,"AB"));
+ pq.push(Node(1,50,"ABC"));
+
+ while(!pq.empty())
+ cout<<pq.top()<<" ", pq.pop();
+ cout<<endl;
+
  return 0;
 }
 

Miscellaneous/01 Operator Overloading for Sorting (Part 2).cpp

@@ -90,6 +90,10 @@ int main()
 {
  optimizeIO();
 
+ /**
+ VECTOR
+ **/
+
  vector<Node>v;
 
  v.push_back(Node(1,100,"C"));
@@ -104,6 +108,10 @@ int main()
 
  cout<<v<<endl;
 
+ /**
+ SET
+ **/
+
  set<Node>st; /** Uses the overloaded < operator **/
  st.insert(Node(1,100,"C"));
  st.insert(Node(1,100,"A"));