C++ Day 39 STL Containers (Deep Understanding & Real Usage) Till now, you already know arrays, vectors, loops, and STL algorithms. Today, we go one step deeper and understand STL containers , which are the backbone of modern C++ programming. In real projects and competitive coding, choice of container matters a lot. 1. What are STL Containers? STL containers are data structures provided by C++ to store data efficiently. They handle: memory management resizing element access performance optimization You focus on logic , not memory handling. 2. Categories of STL Containers STL containers are mainly divided into: Sequence Containers Associative Containers Unordered Containers Container Adapters 3. Sequence Containers These store data in sequence . 3.1 Vector Most used container in C++. vector< int > v; Key Features: Dynamic size Contiguous memory Fast random access Slower insertion in middle Example: v. push_...
You are given an array containing n n n integers. Your task is to determine the longest increasing subsequence in the array, i.e., the longest subsequence where every element is larger than the previous one. A subsequence is a sequence that can be derived from the array by deleting some elements without changing the order of the remaining elements. Input The first line contains an integer n n n : the size of the array. After this there are n n n integers x 1 , x 2 , … , x n x_1,x_2,\ldots,x_n x 1 , x 2 , … , x n : the contents of the array. Output Print the length of the longest increasing subsequence. Constraints 1 ≤ n ≤ 2 ⋅ 1 0 5 1 \le n \le 2 \cdot 10^5 1 ≤ n ≤ 2 ⋅ 1 0 5 1 ≤ x i ≤ 1 0 9 1 \le x_i \le 10^9 1 ≤ x i ≤ 1 0 9 Example Input: 8 7 3 5 3 6 2 9 8 Output: 4 #include < bits / stdc ++. h > using namespace std ; void solve (){ int n ; cin >> n ; vector <int> arr ( n ); for ( int i = 0 ; i < n ; i ++)...