240. Search a 2D Matrix II

Write an efficient algorithm that searches for a target value in an m x n integer matrix. The matrix has the following properties:

• Integers in each row are sorted in ascending from left to right.
• Integers in each column are sorted in ascending from top to bottom.

Example 1:

Input: matrix = [[1,4,7,11,15],[2,5,8,12,19],[3,6,9,16,22],[10,13,14,17,24],[18,21,23,26,30]], target = 5
Output: true

Example 2:

Input: matrix = [[1,4,7,11,15],[2,5,8,12,19],[3,6,9,16,22],[10,13,14,17,24],[18,21,23,26,30]], target = 20
Output: false

Constraints:

• m == matrix.length
• n == matrix[i].length
• 1 <= n, m <= 300
• -109 <= matix[i][j] <= 109
• All the integers in each row are sorted in ascending order.
• All the integers in each column are sorted in ascending order.
• -109 <= target <= 109

# @lc code=start
using LeetCode

function search_matrix(matrix::Matrix{Int}, target::Int)::Bool
    row, col = size(matrix)
    i, j = row, 1

    while (i > 0 && j <= col)
        last = matrix[i, j]

        if (last == target)
            return true
        elseif last > target
            i -= 1
        else
            j += 1
        end
    end

    return false
end
# @lc code=end

search_matrix (generic function with 1 method)

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