Example: Brute-Force Sum of KxK Sub-squares in C++

// Brute-Force Sum of KxK Sub-squares
#include <iostream>
#include <vector>

void findKxKSubsquareSumsBruteForce(const std::vector<std::vector<int>>& matrix, int N, int K) {
    if (K <= 0 || K > N) {
        std::cout << "Invalid K value. K must be between 1 and N." << std::endl;
        return;
    }

    std::cout << "Sums of KxK sub-squares (Brute-Force):" << std::endl;

    // Iterate through all possible top-left corners (i, j) of KxK sub-squares
    // The top-left row 'i' can go from 0 to N-K
    // The top-left column 'j' can go from 0 to N-K
    for (int i = 0; i <= N - K; ++i) {
        for (int j = 0; j <= N - K; ++j) {
            int currentSubsquareSum = 0;
            // Iterate through the elements within the current KxK sub-square
            for (int row = i; row < i + K; ++row) {
                for (int col = j; col < j + K; ++col) {
                    currentSubsquareSum += matrix[row][col];
                }
            }
            std::cout << currentSubsquareSum << " ";
        }
    }
    std::cout << std::endl;
}

int main() {
    // Step 1: Define the matrix and its dimensions
    int N = 3; // Matrix size N x N
    int K = 2; // Sub-square size K x K

    std::vector<std::vector<int>> matrix = {
        {1, 2, 3},
        {4, 5, 6},
        {7, 8, 9}
    };

    // Step 2: Call the brute-force function
    findKxKSubsquareSumsBruteForce(matrix, N, K);

    // Another example
    N = 4;
    K = 3;
    std::vector<std::vector<int>> matrix2 = {
        {1, 1, 1, 1},
        {2, 2, 2, 2},
        {3, 3, 3, 3},
        {4, 4, 4, 4}
    };
    findKxKSubsquareSumsBruteForce(matrix2, N, K);

    return 0;
}