Can I use C++ for LeetCode?

Yes, you can absolutely use C++ for solving problems on LeetCode! C++ is one of the most popular programming languages on the platform due to its speed, flexibility, and powerful STL (Standard Template Library), which provides ready-made data structures and algorithms.

Why C++ is a Good Choice for LeetCode:

1. Fast Execution: C++ is known for its high performance, making it a good choice for coding challenges where time complexity matters, especially when dealing with large datasets.

2. STL (Standard Template Library): C++ provides a robust library that includes data structures like vectors, maps, sets, queues, and algorithms like sorting, binary search, and heap manipulation. This helps reduce coding time and allows you to focus more on problem-solving.

3. Memory Management: C++ allows for fine control over memory usage, which can be crucial in optimizing solutions for certain problems that involve large data sets or tight memory constraints.

4. Object-Oriented and Procedural: C++ offers both object-oriented and procedural programming, giving you flexibility in how you structure your solutions.

How to Use C++ on LeetCode:

1. Select C++ as the Language: When you start solving a problem on LeetCode, you can select C++ from the language dropdown menu in the coding interface.

2. Code in the Online Editor: You can write and test your code directly in LeetCode’s online editor. The editor supports syntax highlighting and basic error checking for C++.

3. Use STL to Your Advantage: Make use of C++’s STL to simplify your code. For example:

   • Use vector instead of manually managing arrays.
   • Use map or unordered_map for hash maps.
   • Use priority_queue for heaps.
   • Use sort function for sorting algorithms.

4. Run and Submit: After writing your code, you can run your solution against sample test cases to check its correctness and then submit it for evaluation against all test cases.

Example of a Simple C++ Solution on LeetCode:

Here’s a basic C++ solution to the "Two Sum" problem, which is one of the most common LeetCode problems:

#include <iostream>
#include <vector>
#include <unordered_map>

using namespace std;

vector<int> twoSum(vector<int>& nums, int target) {
    unordered_map<int, int> numMap; // Stores {value, index}
    for (int i = 0; i < nums.size(); i++) {
        int complement = target - nums[i];
        if (numMap.find(complement) != numMap.end()) {
            return {numMap[complement], i};
        }
        numMap[nums[i]] = i;
    }
    return {}; // If no solution found
}

int main() {
    vector<int> nums = {2, 7, 11, 15};
    int target = 9;
    vector<int> result = twoSum(nums, target);
    cout << result[0] << ", " << result[1] << endl;
    return 0;
}

Conclusion:

C++ is a highly efficient and flexible language for solving LeetCode problems, offering fast execution and helpful libraries through STL. If you’re comfortable with C++, it’s an excellent choice for tackling a wide range of coding challenges on LeetCode.