LeetCode 2392: Build a Matrix With Conditions Solution

Master LeetCode problem 2392 (Build a Matrix With Conditions), a hard challenge, with our optimized solutions in Java, C++, and Python. Explore detailed explanations, test your code in our interactive editor, and prepare for coding interviews.

2392. Build a Matrix With Conditions

Hard

Array Graph Topological Sort Matrix

Problem Explanation

Explanation:

To solve this problem, we need to build a k x k matrix that satisfies the given row and column conditions. We can do this by iteratively placing the numbers in the matrix based on the conditions provided. We can start by creating an empty k x k matrix and then filling it according to the given conditions. If at any point we encounter a conflict where a condition cannot be satisfied, we return an empty matrix.

Create a k x k matrix filled with zeros.
Iterate through the row conditions and place the numbers in the corresponding rows based on the conditions.
Iterate through the column conditions and place the numbers in the corresponding columns based on the conditions.
If there is a conflict at any step, return an empty matrix.

Solution Code

class Solution {
    public int[][] buildMatrix(int k, int[][] rowConditions, int[][] colConditions) {
        int[][] matrix = new int[k][k];

        for (int[] rowCond : rowConditions) {
            int above = rowCond[0] - 1;
            int below = rowCond[1] - 1;
            if (matrix[above][0] != 0 && matrix[below][0] != 0) {
                return new int[][]{};
            }
            matrix[above][0] = below + 1;
        }

        for (int[] colCond : colConditions) {
            int left = colCond[0] - 1;
            int right = colCond[1] - 1;
            if (matrix[0][left] != 0 && matrix[0][right] != 0) {
                return new int[][]{};
            }
            matrix[0][left] = right + 1;
        }

        for (int i = 0; i < k; i++) {
            for (int j = 0; j < k; j++) {
                if (matrix[i][j] == 0) {
                    matrix[i][j] = getMissingNum(k, i, j, matrix);
                }
            }
        }

        return matrix;
    }

    private int getMissingNum(int k, int row, int col, int[][] matrix) {
        for (int num = 1; num <= k; num++) {
            boolean found = false;
            for (int i = 0; i < k; i++) {
                if (matrix[i][col] == num || matrix[row][i] == num) {
                    found = true;
                    break;
                }
            }
            if (!found) {
                return num;
            }
        }
        return -1;
    }
}

Try It Yourself

Loading code editor...

Frequently Asked Questions

How to solve LeetCode 2392 (Build a Matrix With Conditions)?

This page provides optimized solutions for LeetCode problem 2392 (Build a Matrix With Conditions) in Java, C++, and Python, along with a detailed explanation and an interactive code editor to test your code.

What is the time complexity of LeetCode 2392 (Build a Matrix With Conditions)?

The time complexity for LeetCode 2392 (Build a Matrix With Conditions) varies by solution. Check the detailed explanation section for specific complexities in Java, C++, and Python implementations.

Can I run code for LeetCode 2392 on DevExCode?

Yes, DevExCode provides an interactive code editor where you can write, test, and run your code for LeetCode 2392 in Java, C++, or Python.

Back to LeetCode Solutions