Top-K Elements

Key Signals & Indicators

• Problem requires sorting or retrieving the largest/smallest k items
• Finding frequent elements, nearest points, or Kth boundary elements
• Avoids sorting the entire collection in O(n log n)

// C++ Top-K Elements Template
#include <vector>
#include <queue>

std::vector<int> getTopKElements(const std::vector<int>& nums, int k) {
    // Min-heap to keep track of largest elements
    std::priority_queue<int, std::vector<int>, std::greater<int>> minHeap;
    
    for (int num : nums) {
        minHeap.push(num);
        if (minHeap.size() > k) {
            minHeap.pop(); // Keep heap size <= k
        }
    }
    
    std::vector<int> result;
    while (!minHeap.empty()) {
        result.push_back(minHeap.top());
        minHeap.pop();
    }
    return result;
}