New arsenal in cpp

EDA/STL.cpp

@@ -0,0 +1,145 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+// Pairs
+void explainPair(){
+
+    pair<int,int> p = {1,3};
+
+    cout << p.first << " " << p.second << endl;
+
+    pair<int, pair<int, int>> p2 = {1, {3,4}};
+
+    cout << p2.first << " " << p2.second.first << " " << p2.second.second << endl;
+
+    pair<int, int> arr[] = {{1,2}, {2,5}, {5,1}};
+
+    cout << arr[1].first << endl;
+
+}
+
+// Vectors
+void explainVector(){
+
+    vector<int> v;
+
+    v.push_back(1);
+    v.emplace_back(2);
+
+    vector<pair<int,int>> vec;
+
+    // Different in sintax, and emplace creates dinamically
+    vec.push_back({1,2});
+    vec.emplace_back(1,2);
+
+    // Creates a container with 5 spaces, and all've 100 value
+    vector<int> v2(5,100);
+
+    // Creates a container with 5 spaces, all're 0
+    vector<int> v3(5);
+
+    // Copy v2 to v4
+    vector<int> v4(v2);
+
+
+    // interator is a pointer
+    vector<int>::iterator it = v2.begin();
+    cout << *(it) << " ";
+
+    for(vector<int>::iterator it = v2.begin(); it != v2.end(); ++it)
+        cout << *(it) << endl;
+
+    for(auto it = v4.begin(); it != v4.end(); ++it)
+        cout << *(it) << endl;
+
+    // For each loop
+    for(auto x : v4)
+        cout << x << endl;
+
+    // Delete a determinate element
+    v.erase(v.begin()+1);
+
+    // Deleting a range of elements
+    v.erase(v.begin() + 1, v.begin() + 4);
+
+
+    // Insert Function
+    vector<int> vp(5,100); // {100, 100, 100, 100, 100}
+    vp.insert(v.begin(), 300); // {300, 100, 100, 100, 100, 100}
+    vp.insert(v.begin()+1, 2, 10); // {300, 10, 10, 100, 100...}
+
+    // Getting the size of vector
+    vp.size();
+
+    // Deleting the last element
+    vp.pop_back();
+
+    // Change the values of two vectors
+    vp.swap(v);
+
+}
+
+// Lists
+void explainList(){
+
+    list<int> ls;
+
+    ls.push_back(2);
+    ls.emplace_back(4);
+
+    ls.push_front(5);
+    ls.emplace_front();
+
+    // Same functions as vector
+    // We can put elements in front of list
+
+}
+
+
+// Deque
+void explainDeque(){
+
+    deque<int> dq;
+    dq.push_back(1);
+    dq.emplace_back(2);
+    dq.push_front(4);
+    dq.emplace_front(3);
+
+    dq.pop_back();
+    dq.pop_front();
+
+    cout << dq.back() << endl;
+    dq.back();
+    cout << dq.front() << endl;
+    dq.front();
+
+
+    // Same funcitons as vector
+    // This strcutre allows us to put elements in front of it
+    // and remove elements in front, like a double linked list
+
+}
+
+// Priority Queue
+void explainPQ(){
+
+    // The maximum value is in the top of heap
+    priority_queue<int> pq;
+
+    pq.push(5); // {5}
+    pq.push(2); // {5,2}
+    pq.push(3); // {5,3,2}
+    pq.push(10); // {10,5,3,2}
+
+    cout << pq.top() << endl; // prints{10};
+    pq.pop(); // {5,3,2} -> Remove the element in first index
+
+    // Minimum heap
+    priority_queue<int, vector<int>, greater<int>> ppq;
+
+    ppq.push(5); // {5}
+    ppq.push(2); // {2,5}
+    ppq.push(3); // {2,3,5}
+    ppq.push(10); // {2,3,5,10}
+
+}

EDA/maxXor.cpp

@@ -0,0 +1,19 @@
+#include <iostream>
+
+int main(){
+
+    int x, y;
+    int max = 0;
+    std::cin >> x >> y;
+
+    for(int i = x; i <= y; ++i) {
+        for(int j = x; j <= y; ++j) {
+            int currentMax = (i^j);
+            if(currentMax > max)
+                max = currentMax;
+        }
+    }
+
+    std::cout << max << std::endl;
+
+}

EDA/pair_tuples.cpp

@@ -0,0 +1,36 @@
+#include <bits/stdc++.h>
+
+int main(void) {
+
+    // Pairs
+
+    std::pair<std::string, int> mypair1 = std::make_pair("Name", 19);
+    std::cout << mypair1.first << " " << mypair1.second << std::endl;
+
+    mypair1.first = "Its possible change the value after declare a pair";
+
+    std::pair<std::string,std::string> mypair2 = std::make_pair(
+        mypair1.first,"Copyyyy"
+    );
+
+    std::cout << mypair2.first << " " << mypair2.second << std::endl;
+
+    /* OUTPUT
+    Name 19
+    Its possible change the value after declare a pair Copyyyy
+    */
+
+   // Tuples
+   int a = 3, b = 4, c = 5;
+   std::tuple<int, int, int> t{3,4,5};
+
+    // Other form to declare
+    t = std::tie(a,b,c);
+
+    // outputing a tuple
+    std::cout << std::get<0>(t) << std::get<1>(t) << std::get<2>(t) <<
+    std::endl;
+
+
+
+}

EDA/playingWithBits.cpp

@@ -0,0 +1,33 @@
+#include <iostream>
+#include <bitset>
+
+int countSetBits(int n) {
+
+    int count = 0;
+    while(n > 0) {
+        count += (n&1);
+        n = n >> 1;
+    }
+
+    return count;
+}
+
+int main(void) {
+
+    // Basic problems envolving bitwise operations
+    // 1.. Finding the unique number at a sequence
+    // 2.. S compliment
+    //3.. odd or even
+
+    // Playing with bits, how many bits have (a to b)
+    int a,b;
+    int count = 0;
+    std::cin >> a >> b;
+
+    for(int i = a; i <= b; ++i)
+        count += countSetBits(i);
+
+    std::cout << count << std::endl;
+
+
+}