Top 10 most used inbuilt C++ functions for Competitive Programming

In this article, we will discuss the top 10 most used inbuilt C++ functions for Competitive Programming.

Introduction of Inbuilt C++ Functions

In C++, integrated features are generally called general library features or features furnished via the C++ Standard Template Library (STL). These features cover an extensive variety of duties and operations, making it less difficult for builders to carry out unusual place operations while not having to enforce them from scratch.

Top 10 most used inbuilt C++ functions for Competitive Programming

Key factors of in-built features in C++:

Here are a few key factors approximately in-built features in C++:

Standard Library (STL):

The C++ Standard Library is a group of pre-constructed lessons and features that offer unusual place functionality. It is a part of the C++ language in general and is on the market for all C++ programs.

Header Files:

If you want to use those features, you want to encompass the suitable header documents on your program. For example, the header affords features for enter and output operations, affords dynamic arrays, and gives numerous algorithms.

Namespace:

Most of the usual features are described with inside the std::namespace. It offers the space where we can define the identifier i.e., method, variables, and classes.

Common Inbuilt Functions:

There are several common in-built functions in C++. Some main common in-built functions are as follows:

Input/Output: Functions like cin and cout for console enter and output.
Containers: Functions for running with bins like vectors, arrays, lists, etc.
Algorithms: Sorting (sort), searching (find), and different algorithms.
String Handling: Functions for string manipulation (length, substr, etc.).
Mathematics: Mathematical features which include sqrt, sin, cos, etc.
Memory Management: Functions like new and delete for dynamic reminiscence allocation.

Top 10 most used in-built C++ functions for competitive programming

In aggressive programming, builders frequently depend upon a hard and fast of typically used C++ features from the Standard Template Library (STL) to efficiently clear up problems. Here's a listing of 10 often used in-built features in C++ for aggressive programming:

1. Input/ Output function in C++:

In C++, input and output operations are usually done with the usage of the header, which affords the "cin" and "cout" items for studying from and writing to the usual enter and output streams.

Example:

#include <iostream>
int main() {
 int x;
 std::cout << "Enter a number: ";
 std::cin >> x;
 std::cout << "You entered: " << x << std::endl;
return 0;
}

Output:

Enter a number: [User input]
You entered: [The value entered by the user]

2. Vector function ("vector")

In C++, vectors are a part of the Standard Template Library (STL) and offer a dynamic array implementation. They are exceptionally flexible and extensively used for diverse programming tasks. Here are a few normally used capabilities and operations with vectors in C++:

#include <vector>
std::vector<int> numbers = {1, 2, 3, 4, 5};#include <iostream>
#include <vector>
int main() {
 std::vector<int> numbers = {1, 2, 3, 4, 5};
 // Print the elements of the vector
 std::cout << "Elements of the vector: ";
 for (int num : numbers) {
 std::cout << num << " ";
 }
 std::cout << std::endl;

 return 0;
}

Output:

Elements of the vector: 1 2 3 4 5

3. Sorting function ("sort")

In C++, the sort feature is a part of the header and is used to type the factors of a selection in ascending order via way of means of default. Here's an instance of the way to use the kind feature:

#include <algorithm>
std::sort(v.begin(), v.end());

4. Searching function:

In C++, the header presents numerous features for looking at factors in a range. Two normally used searching features are std::discover and std::binary_search.

Example:

#include <algorithm>

if (std::binary_search(v.begin(), v.end(), 3)) {
 // Element found
}

auto it = std::find(v.begin(), v.end(), 2);

5. Pair Function

In C++, the std::pair is a template elegance described in the header that permits you to keep heterogeneous items as an unmarried entity. It is regularly used to symbolize a couple of values. Here's an easy instance demonstrating using std::pair:

Example:

#include <iostream>
#include <utility> // Include the <utility> header for std::pair

int main() {
 // Create a pair of integers
 std::pair<int, int> coordinates = std::make_pair(3, 5);

 // Access elements of the pair
 int x = coordinates.first;
 int y = coordinates.second;

 // Print the pair values
 std::cout << "Coordinates: (" << x << ", " << y << ")" << std::endl;

 return 0;
}

Output:

Coordinates: (3, 5)

6. Maps

In C++, the Standard Template Library (STL) presents a map field that implements taken care associative field. It shops key-price pairs and lets in for green retrieval of values primarily based totally on their related keys. Here's a quick review of a way to use std::map in C++:

Example:

#include <iostream>
#include <map>
int main() {
 std::map<int, std::string> studentMap = {
 {101, "John"},
 {102, "Alice"},
 {103, "Bob"}
 };

 // Accessing elements
 std::cout << "Student 102: " << studentMap[102] << std::endl;

 // Iterating through the map
 for (const auto& pair : studentMap) {
 std::cout << "ID: " << pair.first << ", Name: " << pair.second << std::endl;
 }

 return 0;
}

Output:

Student 102: Alice
ID: 101, Name: John
ID: 102, Name: Alice
ID: 103, Name: Bob

7. Sets

In C++, the std::set is a well-known standard template library (STL) field that represents a looked after associative field containing precise elements. Here's an instance software demonstrating the usage of std::set:

Example:

#include <iostream>
#include <set>
int main() {
 // Declare and initialize a set of integers
 std::set<int> mySet = {30, 10, 50, 20, 40, 30};

 // Print elements in the set
 std::cout << "Elements in the set:";
 for (const auto& element : mySet) {
 std::cout << " " << element;
 }
 std::cout << std::endl;

 // Check if an element is present in the set
 int searchElement = 20;
 if (mySet.find(searchElement) != mySet.end()) {
 std::cout << searchElement << " is present in the set." << std::endl;
 } else {
 std::cout << searchElement << " is not present in the set." << std::endl;
 }

 // Erase an element from the set
 mySet.erase(30);

 // Print the set after erasing an element
 std::cout << "Elements in the set after erasing 30:";
 for (const auto& element : mySet) {
 std::cout << " " << element;
 }
 std::cout << std::endl;

 return 0;
}

Output:

Elements in the set: 10 20 30 40 50
20 is present in the set.
Elements in the set after erasing 30: 10 20 40 50

8. Queue and stack

Queue("queue"): A queue is a linear statistics shape that follows the First-In-First-Out (FIFO) principle. In a queue, factors are delivered on the rear (enqueue) and eliminated from the front (dequeue). It's like a real global queue or line, in which the individual that arrives first is the primary to be served.

Stack("stack"): A stack is a linear data structure that follows the Last-in-First-Out (LIFO) principle. In a stack, elements are added or removed from the top of the stack. It's like a plate stack where you can only take the top plate.

Example:

#include <iostream>
#include <queue>
int main() {
 std::queue<int> myQueue;
 myQueue.push(10);
 myQueue.push(20);
 myQueue.push(30);

 while (!myQueue.empty()) {
 std::cout << myQueue.front() << " ";
 myQueue.pop();
 }

 return 0;
}

Output:

10 20 30

9. String manipulation

In C++, String manipulation may be accomplished the usage of the header and diverse string capabilities supplied with the aid of using the C++ Standard Library. Below are a few generally used string manipulation capabilities in C++:

Example:

#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <sstream>

int main() {
 // Concatenation
 std::string result = "Hello, " + "World!";
 std::cout << "Concatenation: " << result << std::endl;

 // String Length
 std::string myString = "Hello, World!";
 std::cout << "Length: " << myString.length() << std::endl;

 // Substring Extraction
 std::cout << "Substring: " << myString.substr(7, 5) << std::endl;

 // String Comparison
 std::cout << "Comparison Result: " << "apple".compare("banana") << std::endl;

 // String Searching
 std::cout << "Search Position: " << myString.find("World") << std::endl;

 // String Replacement
 myString.replace(7, 5, "Universe");
 std::cout << "After Replacement: " << myString << std::endl;

 // String to Integer Conversion
 std::cout << "Integer Conversion: " << std::stoi("123") << std::endl;

 // Character Removal
 std::string stringWithSpaces = "Remove spaces from here";
 stringWithSpaces.erase(std::remove(stringWithSpaces.begin(), stringWithSpaces.end(), ' '), stringWithSpaces.end());
 std::cout << "After Removing Spaces: " << stringWithSpaces << std::endl;

 // String Tokenization
 std::istringstream iss("apple orange banana");
 std::vector<std::string> tokens{std::istream_iterator<std::string>{iss}, std::istream_iterator<std::string>{}};
 std::cout << "Tokenization:";
 for (const auto& token : tokens) std::cout << " " << token;
 std::cout << std::endl;

 // String Conversion to Uppercase/Lowercase
 std::string str = "Convert Me";
 std::transform(str.begin(), str.end(), str.begin(), ::toupper);
 std::cout << "Uppercase: " << str << std::endl;

 std::transform(str.begin(), str.end(), str.begin(), ::tolower);
 std::cout << "Lowercase: " << str << std::endl;

 return 0;
}

Output:

Concatenation: Hello, World!
Length: 13
Substring: World
Comparison Result: -1
Search Position: 7
After Replacement: Hello, Universe!
Integer Conversion: 123
After Removing Spaces: Removespacesfromhere
Tokenization: apple orange banana
Uppercase: CONVERT ME TO UPPERCASE
Lowercase: convert me to lowercase

10. Math functions

In C++, math functions are an integral part of the standard library and are primarily defined by "cmath" header ("math" in C). These functions cover a wide range of mathematical operations, from basic arithmetic to advanced mathematical calculations. Here is a brief introduction to some of the more common math functions in C++:

Example:

#include <iostream>
#include <cmath>
int main () {
 // Arithmetic operations
 int a = 10, b = 3;
 double result_addition = a + b;
 double result_subtraction = a - b;
 double result_multiplication = a * b;
 double result_division = static_cast<double>(a) / b;

 std::cout << "Arithmetic Operations:\n";
 std::cout << "Addition: " << result_addition << "\n";
 std::cout << "Subtraction: " << result_subtraction << "\n";
 std::cout << "Multiplication: " << result_multiplication << "\n";
 std::cout << "Division: " << result_division << "\n\n";

 // Power and Exponentiation
 double base = 2.0, exponent = 3.0;
 double result_power = std::pow(base, exponent);
 double result_sqrt = std::sqrt(16.0);

 std::cout << "Power and Exponentiation:\n";
 std::cout << "Power: " << result_power << "\n";
 std::cout << "Square Root: " << result_sqrt << "\n\n";

 // Trigonometric Functions
 double angle_degrees = 45.0;
 double angle_radians = angle_degrees * M_PI / 180.0;
 double result_sin = std::sin(angle_radians);
 double result_cos = std::cos(angle_radians);
 double result_tan = std::tan(angle_radians);

 std::cout << "Trigonometric Functions:\n";
 std::cout << "Sine: " << result_sin << "\n";
 std::cout << "Cosine: " << result_cos << "\n";
 std::cout << "Tangent: " << result_tan << "\n\n";

 // Logarithmic Functions
 double value_log = 10.0;
 double result_log = std::log(value_log);
 double result_log10 = std::log10(value_log);

 std::cout << "Logarithmic Functions:\n";
 std::cout << "Natural Logarithm: " << result_log << "\n";
 std::cout << "Log Base 10: " << result_log10 << "\n\n";

 // Rounding Functions
 double value_round = 4.6;
 double result_ceil = std::ceil(value_round);
 double result_floor = std::floor(value_round);
 double result_round = std::round(value_round);

 std::cout << "Rounding Functions:\n";
 std::cout << "Ceil: " << result_ceil << "\n";
 std::cout << "Floor: " << result_floor << "\n";
 std::cout << "Round: " << result_round << "\n";

 return 0;
}

Output:

Arithmetic Operations:
Addition: 13
Subtraction: 7
Multiplication: 30
Division: 3.33333

Power and Exponentiation:
Power: 8
Square Root: 4

Trigonometric Functions:
Sine: 0.707107
Cosine: 0.707107
Tangent: 1

Logarithmic Functions:
Natural Logarithm: 2.30259
Log Base 10: 1

Rounding Functions:
Ceil: 5
Floor: 4
Round: 5

Conclusion:

Competitive programming requires a powerful arsenal of C++ functions to move quickly and efficiently through complex problem-solving scenarios. The primary importance are the input and output current functions cin and cout, which are known for their speed and simplicity. Unlike their scan-and-print counterparts, these features offer a faster I/O mechanism, a critical factor in time-sensitive competitions where milliseconds can make a big difference. They form the backbone of any solution, seamlessly handling user inputs and outputs with unmatched efficiency.

Container manipulation is a cornerstone of concurrent programming, and the vector class is distinguished from a dynamic set, which provides continuous random access. Its resizing capabilities make it a versatile choice that adapts to ever-changing algorithmic challenges. In addition, the String class provides a wealth of functions for handling strings, providing a powerful tool for text processing and manipulation tasks. Algorithms are at the heart of problem-solving, and C++ provides a set of functions <algorithm> title Sorting, translating, and searching elements becomes trivial with sorting, translating, and searching functions.

In particular, sorting is a key feature of many problems, and C++'s powerful sorting algorithm ensures optimal performance even under tight time constraints. <cmath> library introduces the mathematical functions needed to solve numerical calculation problems. These tools allow developers to solve various mathematical challenges, from basic arithmetic operations to advanced trigonometric functions (sin, cos, tan) and logarithmic functions (log, log10). However, it is important to note that trigonometric functions usually assume angles in radians, which requires careful conversion for problems involving degrees. Row and stack operations are crucial to the implementation of the data structures required by many algorithms. C++ provides easy-to-use interfaces with queue and stack classes that simplify the implementation of breadth-first and depth-first search algorithms and solve problems where these constructs prove invaluable. Sets and cards <set> and <map> headers are important for handling unique keys and association containers. The set class ensures that elements are unique, while the map class associates values with unique keys, providing an efficient way to manage data relationships. These containers are often crucial for effectively solving problems where the uniqueness of elements or relationships is key. Iterators like begin () and end () provide a clean and concise way to iterate through containers, making it easier to iterate over elements. Efficient iteration is critical to many algorithms, and C++ iterators provide a unified interface that improves code readability and maintainability. Bitwise operations (&, |, ^, <<, >>) open the gate to precise manipulation of binary data. In competitive programming, where bit manipulation can significantly optimize solutions, understanding and using these features can lead to more efficient and elegant code.

Finally, the conditional operator acts as a summary marker for formatting conditional expressions. Its concise syntax allows programmers to elegantly express conditional logic, reducing code verbosity without sacrificing clarity. Finally, the 10 most used built-in C++ functions for competitive programming form a powerhouse that allows programmers to effectively address a variety of challenges. Whether handling input and output, working with containers, using algorithms, performing mathematical calculations, managing data structures, or creating summary expressions, these functions are essential tools in a competitive developer's arsenal. Mastery of these functions, along with an understanding of their complexity and time complexity, allows programmers to navigate the complexities of competitive programming with finesse and precision.

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