Package g1401_1500.s1439_find_the_kth_smallest_sum_of_a_matrix_with_sorted_rows

Class Solution

  • public class Solution
extends Object
    1439 - Find the Kth Smallest Sum of a Matrix With Sorted Rows.

    Hard

    You are given an m x n matrix mat that has its rows sorted in non-decreasing order and an integer k.

    You are allowed to choose exactly one element from each row to form an array.

    Return the kth smallest array sum among all possible arrays.

    Example 1:

    Input: mat = [[1,3,11],[2,4,6]], k = 5

    Output: 7

    Explanation: Choosing one element from each row, the first k smallest sum are: [1,2], [1,4], [3,2], [3,4], [1,6]. Where the 5th sum is 7.

    Example 2:

    Input: mat = [[1,3,11],[2,4,6]], k = 9

    Output: 17

    Example 3:

    Input: mat = [[1,10,10],[1,4,5],[2,3,6]], k = 7

    Output: 9

    Explanation: Choosing one element from each row, the first k smallest sum are: [1,1,2], [1,1,3], [1,4,2], [1,4,3], [1,1,6], [1,5,2], [1,5,3]. Where the 7th sum is 9.

    Constraints:

    • m == mat.length
    • n == mat.length[i]
    • 1 <= m, n <= 40
    • 1 <= mat[i][j] <= 5000
    • 1 <= k <= min(200, nm)
    • mat[i] is a non-decreasing array.

    • Constructor Detail

      • Solution

        public Solution()

    • Method Detail

      • kthSmallest

        public int kthSmallest​(int[][] mat,
                       int k)