trees,dp,common codes etc

Author: Prateek Narang

Queue/1. Queue using Array.cpp

@@ -31,10 +31,13 @@ void deQueue(Queue &Q){
         return ;
     }
     Q.front++;
+
     if(Q.front==100){
      Q.front = 0;
     }
+
     Q.currentSize--;
+
     if(Q.currentSize==0){
         Q.front = 0;
         Q.rear = -1;

Queue/2. Reverse A Queue Using Recursion.cpp

@@ -74,7 +74,6 @@ deQueue(Q);
 enQueue(Q,5);
 recursiveReverse(Q);
 print(Q);
-
 }
 
 

Recursion/11. Generate all subsequences of a string

@@ -26,7 +26,7 @@ void printSubsequences(char *s,char *temp,int start_index,int temp_index,int len
 
 
 int main(){
-char s[20]="hello";
+char s[20]="abc";
 char temp[20];
 int len = strlen(s);
 printSubsequences(s,temp,0,-1,len);

Recursion/11. Generate all subsequences of a string.cpp

@@ -36,8 +36,37 @@ adj[dest].push_back(n1);
 }
 
 
+/*
+void disjkstra2(int s,int V=9){
+bool visited[100]={0};
+memset(dist,INT_MAX,sizeof dist);
+
+priority_queue<int,vector<int>,myComparison> q;
 
+dist[s]=0;
+visited[s]=true;
+for(int i=0;i<V;i++){
+    q.push(i);
+}
 
+while(!q.empty()){
+    int cur = q.top();
+    q.pop();
+
+    visited[cur]=true;
+
+    for(int j=0;j<adj[cur].size();j++){
+       int des = adj[cur][j].dest;
+       int wt = adj[cur][j].wt;
+
+       if(dist[cur]+wt < dist[des]&&visited[des]==false){
+        dist[des] = dist[cur]+wt;
+       }
+    }
+}
+
+}
+*/
 
 
 void dijkstra(int s){
@@ -78,29 +107,55 @@ while(!q.empty()){
 
 }
 
+}
+/*
+void test_func(){
+int v1=15;
+int v2 = 16;
 
 
-}
+priority_queue<int,vector<int>,myComparison> q;
+dist[15] = 10;
+dist[16] = 16;
+
+
+q.push(v1);
+q.push(v2);
+
+dist[15]=100;
+
+cout<<"In test function ";
+while(!q.empty()){
+        cout<<q.top()<<endl;
+        q.pop();
+
+    }
 
+}
+*/
 int main(){
 int V = 9;
-    addEdge( 0, 1, 4);
+    addEdge(0, 1, 4);
     addEdge(0, 7, 8);
-    addEdge( 1, 2, 8);
-    addEdge( 1, 7, 11);
-    addEdge( 2, 3, 7);
-    addEdge( 2, 8, 2);
-    addEdge( 2, 5, 4);
+    addEdge(1, 2, 8);
+    addEdge(1, 7, 11);
+    addEdge(2, 3, 7);
+    addEdge(2, 8, 2);
+    addEdge(2, 5, 4);
     addEdge(3, 4, 9);
-    addEdge( 3, 5, 14);
-    addEdge( 4, 5, 10);
-    addEdge( 5, 6, 2);
-    addEdge( 6, 7, 1);
-    addEdge( 6, 8, 6);
-    addEdge( 7, 8, 7);
-    dijkstra(0);
+    addEdge(3, 5, 14);
+    addEdge(4, 5, 10);
+    addEdge(5, 6, 2);
+    addEdge(6, 7, 1);
+    addEdge(6, 8, 6);
+    addEdge(7, 8, 7);
+    //dijkstra(0);
+
 int i;
 for(i=0;i<V;i++)
     cout<<i<<" "<<dist[i]<<endl;
+
+test_func();
+
 return 0;
 }

Recursion/11. Generate all subsequences of a string.o

@@ -4,6 +4,7 @@
 #include<queue>
 #include<cstring>
 #define INT_MAX 1000000000
+#include<functional>
 using namespace std;
 
 

Shortest Paths/Dijkshtra Adjaceny List and Heap (ELogV).cpp

@@ -1,9 +1,45 @@
 #include<iostream>
-#include<stack>
+#include "stack_using_node.h"
 using namespace std;
 
+//----------------------------------------Recursive Implementation
+void insertAtBottom(stack_using_node<int> &s,int data){
+   int temp;
+   if(s.isEmpty()))
+   {
+       s.push(data);
+   }
+   else
+   {
+     int temp = s.pop();
+     insertAtBottom(s,data);
+     s.push(data);
+   }
+}
+
+
+void reverseStack(stack_using_node<int> &s){
+if(!s.isEmpty()){
+
+        int top = s.pop();
+        reverseStack(s);
+        insertAtBottom(top);
+
+    }
+}
+//----------------------------------------------Non Recursive Implemenation
+
 
 int main(){
+stack_using_node<int> s;
+s.push(1);
+s.push(2);
+s.push(3);
 
+reverseStack(s);
 
+while(!s.isEmpty()){
+    cout<<s.pop();
+}
+return 0;
 }