added hackerrank solutions

HackerRank/Delete a node.cpp

@@ -0,0 +1,18 @@
+
+
+
+SinglyLinkedListNode* deleteNode(SinglyLinkedListNode* llist, int position) {
+int cnt=0;
+SinglyLinkedListNode* temp=llist;
+
+while(cnt<position-1){
+    temp=temp->next;
+    cnt++;
+}
+if(position==0) {
+    llist=temp->next;
+}
+temp->next=temp->next->next;
+
+return llist;
+}

HackerRank/Left Rotation.cpp

@@ -0,0 +1,18 @@
+#include <iostream>
+using namespace std;
+#include <vector>
+int main(){
+    int n1,n2;
+    cin>>n1>>n2;
+    vector <int> vect(n1);
+    for(int i=0;i<n1;++i){
+        cin>>vect[i];
+    }
+    n2=n2%n1;
+    for(int j=n2;j<n1;++j){
+        cout<<vect[j]<<" ";
+    }
+    for(int j=0;j<n2;++j){
+        cout<<vect[j]<<" ";
+    }
+}

HackerRank/arrays-DS.cpp

@@ -0,0 +1,100 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+string ltrim(const string &);
+string rtrim(const string &);
+vector<string> split(const string &);
+
+/*
+ * Complete the 'reverseArray' function below.
+ *
+ * The function is expected to return an INTEGER_ARRAY.
+ * The function accepts INTEGER_ARRAY a as parameter.
+ */
+
+vector<int> reverseArray(vector<int> a) {
+vector<int>result;
+for(int i=a.size()-1;i>=0;i--){
+    result.push_back(a[i]);
+}
+return result;
+}
+
+int main()
+{
+    ofstream fout(getenv("OUTPUT_PATH"));
+
+    string arr_count_temp;
+    getline(cin, arr_count_temp);
+
+    int arr_count = stoi(ltrim(rtrim(arr_count_temp)));
+
+    string arr_temp_temp;
+    getline(cin, arr_temp_temp);
+
+    vector<string> arr_temp = split(rtrim(arr_temp_temp));
+
+    vector<int> arr(arr_count);
+
+    for (int i = 0; i < arr_count; i++) {
+        int arr_item = stoi(arr_temp[i]);
+
+        arr[i] = arr_item;
+    }
+
+    vector<int> res = reverseArray(arr);
+
+    for (size_t i = 0; i < res.size(); i++) {
+        fout << res[i];
+
+        if (i != res.size() - 1) {
+            fout << " ";
+        }
+    }
+
+    fout << "\n";
+
+    fout.close();
+
+    return 0;
+}
+
+string ltrim(const string &str) {
+    string s(str);
+
+    s.erase(
+        s.begin(),
+        find_if(s.begin(), s.end(), not1(ptr_fun<int, int>(isspace)))
+    );
+
+    return s;
+}
+
+string rtrim(const string &str) {
+    string s(str);
+
+    s.erase(
+        find_if(s.rbegin(), s.rend(), not1(ptr_fun<int, int>(isspace))).base(),
+        s.end()
+    );
+
+    return s;
+}
+
+vector<string> split(const string &str) {
+    vector<string> tokens;
+
+    string::size_type start = 0;
+    string::size_type end = 0;
+
+    while ((end = str.find(" ", start)) != string::npos) {
+        tokens.push_back(str.substr(start, end - start));
+
+        start = end + 1;
+    }
+
+    tokens.push_back(str.substr(start));
+
+    return tokens;
+}

HackerRank/insert a node at a specific position in a linked list.cpp

@@ -0,0 +1,30 @@
+
+/*
+ * For your reference:
+ *
+ * SinglyLinkedListNode {
+ *     int data;
+ *     SinglyLinkedListNode* next;
+ * };
+ *
+ */
+
+SinglyLinkedListNode* insertNodeAtPosition(SinglyLinkedListNode* llist, int data, int position) {
+     SinglyLinkedListNode*temp=llist;
+     int cnt=0;
+      SinglyLinkedListNode*node1=new  SinglyLinkedListNode(data);
+    if(position==1){
+        node1->next=llist;
+        llist=node1;
+    }
+    else{
+       while(cnt<position-1) {
+           cnt++;
+           temp=temp->next;
+       }
+       node1->next=temp->next;
+       temp->next=node1;
+       }
+
+   return llist;
+}

HackerRank/insert the node at head of linked list.cpp

@@ -0,0 +1,6 @@
+SinglyLinkedListNode* insertNodeAtHead(SinglyLinkedListNode* llist, int data) {
+        SinglyLinkedListNode* temp=new SinglyLinkedListNode(data);
+        temp->next=llist;
+        llist=temp;
+        return llist;
+}

HackerRank/insert the node at the tail of linked list.cpp

@@ -0,0 +1,15 @@
+SinglyLinkedListNode*insertNodeAtTail( SinglyLinkedListNode* head,int data){
+     SinglyLinkedListNode*temp=head;
+      SinglyLinkedListNode*node1=new  SinglyLinkedListNode(data);
+     if(head==0){
+         head=node1;
+     }
+     else{
+         while(temp->next!=NULL){
+             temp=temp->next;
+         }
+         temp->next=node1;
+
+     }
+     return head;
+ }

HackerRank/print in reverse.cpp

@@ -0,0 +1,18 @@
+SinglyLinkedListNode* reversePrint(SinglyLinkedListNode* llist) {
+        if(llist==NULL || llist->next==NULL){
+        return llist;
+    }
+SinglyLinkedListNode* curr=llist;
+SinglyLinkedListNode* prev=NULL;
+SinglyLinkedListNode* forward=NULL;
+
+while(curr!=NULL){
+    forward=curr->next;
+    curr->next=prev;
+    prev=curr;
+    curr=forward;
+
+
+}
+return prev;
+}

HackerRank/print the element of linked list.cpp

@@ -0,0 +1,10 @@
+void printLinkedList(SinglyLinkedListNode* head) {
+    SinglyLinkedListNode*temp=head;
+    while(temp!=NULL){
+        cout<<temp->data<<endl;;
+        temp=temp->next;
+    }
+
+
+
+}

HackerRank/reverse a linked list.cpp

@@ -0,0 +1,20 @@
+
+
+SinglyLinkedListNode* reverse(SinglyLinkedListNode* llist) {
+       if(llist==NULL || llist->next==NULL){
+        return llist;
+    }
+SinglyLinkedListNode* curr=llist;
+SinglyLinkedListNode* prev=NULL;
+SinglyLinkedListNode* forward=NULL;
+
+while(curr!=NULL){
+    forward=curr->next;
+    curr->next=prev;
+    prev=curr;
+    curr=forward;
+
+
+}
+return prev;
+}