Add recursion

Author: 31Sanskrati

Recursion/count_paths.cpp renamed to Advanced Recursion/count_paths.cpp

@@ -0,0 +1,6 @@
+{
+    "files.associations": {
+        "iostream": "cpp",
+        "ostream": "cpp"
+    }
+}

Recursion/n-queen_problem.cpp renamed to Advanced Recursion/n-queen_problem.cpp

@@ -0,0 +1,20 @@
+#include <iostream>
+using namespace std;
+
+void printTillN(int n){
+    //base case
+    if(n==0){
+        return;
+    }
+    //work
+    cout<<n<<" ";
+    //recursive call
+    printTillN(n-1);
+}
+
+int main(){
+    int n;
+    cout<<"Enter a number"<<endl;
+    cin>>n;
+    printTillN(n);
+}

Recursion/path_maze.cpp renamed to Advanced Recursion/path_maze.cpp

@@ -0,0 +1,66 @@
+#include <iostream>
+using namespace std;
+
+string spelling(int curr)
+{
+    if (curr == 1)
+    {
+        return "One ";
+    }
+    else if (curr == 2)
+    {
+        return "Two ";
+    }
+    else if (curr == 3)
+    {
+        return "Three ";
+    }
+    else if (curr == 4)
+    {
+        return "Four ";
+    }
+    else if (curr == 5)
+    {
+        return "Five ";
+    }
+    else if (curr == 6)
+    {
+        return "Six ";
+    }
+    else if (curr == 7)
+    {
+        return "Seven ";
+    }
+    else if (curr == 8)
+    {
+        return "Eight ";
+    }
+    else if (curr == 9)
+    {
+        return "Nine ";
+    }
+    else if (curr == 0)
+    {
+        return "Zero ";
+    }
+}
+
+void printSpelling(int n)
+{
+    n = n / 10;
+    string s = "";
+    if (n < 1)
+    {
+        s = s + spelling(n % 10);
+        return;
+    }
+    int curr = n % 10;
+    s = s + spelling(curr);
+    printSpelling(n);
+    cout << s;
+}
+
+int main()
+{
+    printSpelling(120);
+}

Recursion/rat_in_maze.cpp renamed to Advanced Recursion/rat_in_maze.cpp

@@ -0,0 +1,6 @@
+{
+    "files.associations": {
+        "ostream": "cpp",
+        "iostream": "cpp"
+    }
+}

Recursion/tower_of_hanoi.cpp renamed to Advanced Recursion/tower_of_hanoi.cpp

@@ -0,0 +1,16 @@
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+int main(){
+    vector<int> vec;
+    cout<<vec.max_size()<<endl; //2305843009213693951
+
+    for (int i = 1; i<=5; i++){
+        vec.push_back(i);
+    }
+    cout<<vec.size()<<endl; //5
+    cout<<vec.capacity()<<endl; //8
+    cout<<vec.empty()<<endl; //0
+}

Recursion/.vscode/settings.json

@@ -0,0 +1,35 @@
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+/*Vectors are same as dynamic arrays with the ability to resize itself automatically when an element is inserted or deleted, with their storage being handled automatically by the container.
+Vector elements are placed in contiguous storage so that they can be accessed and traversed using iterators. In vectors, data is inserted at the end.
+*/
+
+
+int main()
+{
+	vector<int> g1;
+
+	for (int i = 1; i <= 5; i++)
+		g1.push_back(i);
+
+	cout << "Output of begin and end: ";
+	for (auto i = g1.begin(); i != g1.end(); ++i)
+		cout << *i << " ";
+
+	cout << "\nOutput of cbegin and cend: ";
+	for (auto i = g1.cbegin(); i != g1.cend(); ++i)
+		cout << *i << " ";
+
+	cout << "\nOutput of rbegin and rend: ";
+	for (auto ir = g1.rbegin(); ir != g1.rend(); ++ir)
+		cout << *ir << " ";
+
+	cout << "\nOutput of crbegin and crend : ";
+	for (auto ir = g1.crbegin(); ir != g1.crend(); ++ir)
+		cout << *ir << " ";
+
+	return 0;
+}

Recursion/counting.cpp

@@ -0,0 +1,25 @@
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+void print(vector<int> v){
+    for (int i = 0; i < v.size(); i++)
+        cout << v[i] << " ";
+    cout<<endl;
+}
+
+int main()
+{
+	vector<int> v;
+    v.assign(8, 2);
+    cout << "The vector elements are: ";
+    print(v); //2 2 2 2 2 2 2 2 
+    v.push_back(10);
+    print(v); //2 2 2 2 2 2 2 2 10
+    v.pop_back();
+    v.insert(v.begin(), 0);
+    print(v); //0 2 2 2 2 2 2 2 2
+    
+    return 0;
+}