Package g2301_2400.s2392_build_a_matrix_with_conditions

Class Solution

java.lang.Object
g2301_2400.s2392_build_a_matrix_with_conditions.Solution
public class Solution extends java.lang.Object
2392 - Build a Matrix With Conditions.

Hard

You are given a positive integer k. You are also given:

  • a 2D integer array rowConditions of size n where rowConditions[i] = [abovei, belowi], and
  • a 2D integer array colConditions of size m where colConditions[i] = [lefti, righti].

The two arrays contain integers from 1 to k.

You have to build a k x k matrix that contains each of the numbers from 1 to k exactly once. The remaining cells should have the value 0.

The matrix should also satisfy the following conditions:

  • The number abovei should appear in a row that is strictly above the row at which the number belowi appears for all i from 0 to n - 1.
  • The number lefti should appear in a column that is strictly left of the column at which the number righti appears for all i from 0 to m - 1.

Return any matrix that satisfies the conditions. If no answer exists, return an empty matrix.

Example 1:

Input: k = 3, rowConditions = [[1,2],[3,2]], colConditions = [[2,1],[3,2]]

Output: [[3,0,0],[0,0,1],[0,2,0]]

Explanation: The diagram above shows a valid example of a matrix that satisfies all the conditions.

The row conditions are the following:

  • Number 1 is in row 1, and number 2 is in row 2, so 1 is above 2 in the matrix.

  • Number 3 is in row 0, and number 2 is in row 2, so 3 is above 2 in the matrix.

The column conditions are the following:

  • Number 2 is in column 1, and number 1 is in column 2, so 2 is left of 1 in the matrix.

  • Number 3 is in column 0, and number 2 is in column 1, so 3 is left of 2 in the matrix.

Note that there may be multiple correct answers.

Example 2:

Input: k = 3, rowConditions = [[1,2],[2,3],[3,1],[2,3]], colConditions = [[2,1]]

Output: []

Explanation: From the first two conditions, 3 has to be below 1 but the third conditions needs 3 to be above 1 to be satisfied.

No matrix can satisfy all the conditions, so we return the empty matrix.

Constraints:

  • 2 <= k <= 400
  • 1 <= rowConditions.length, colConditions.length <= 104
  • rowConditions[i].length == colConditions[i].length == 2
  • 1 <= abovei, belowi, lefti, righti <= k
  • abovei != belowi
  • lefti != righti

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    int[][]
    buildMatrix(int k, int[][] rowC, int[][] colC)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • buildMatrix

      public int[][] buildMatrix(int k, int[][] rowC, int[][] colC)