Search a 2D Matrix II

Write an efficient algorithm that searches for a value in an m x n matrix. This 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.

• Time: O(n)
• Space: O(1)

public boolean searchMatrix(int[][] matrix, int target) {
    int m = matrix.length, n = matrix[0].length, i = 0, j = n - 1;
    while (i < m && j >= 0) {
        if (matrix[i][j] == target)
            return true;
        else if (matrix[i][j] < target)
            i++;
        else
            j--;
    }
    return false;
}