(LeetCode) 240. Search a 2D Matrix II

240. Search a 2D Matrix II

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• 분류 : Sorting and Searching
• 난이도 : Medium

Problem

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
• -10^9 <= matix[i][j] <= 10^9
• All the integers in each row are sorted in ascending order.
• All the integers in each column are sorted in ascending order.
• -10^9 <= target <= 10^9

Solution

Exapnder

class Solution {
    fun searchMatrix(matrix: Array<IntArray>, target: Int): Boolean {
        matrix.forEach { 
            if (it.contains(target)) {
                return true
            }
        }
        return false
    }
}

Point of Thinking

• 2차원 배열 matrix를 순회하면서, target이 존재하나 검증하면 Accepted.