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Behavioral

For the following matrix:

$$
\begin{bmatrix}
21 & 14 \\
19 & 10 \\
11 & 15 \\
\end{bmatrix}
$$

What is the output?

For the following matrix:
<math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mo fence="true">[</mo><mtable rowspacing="0.16em" columnalign="center center" columnspacing="1em"><mtr><mtd><mstyle scriptlevel="0" displaystyle="false"><mn>21</mn></mstyle></mtd><mtd><mstyle scriptlevel="0" displaystyle="false"><mn>14</mn></mstyle></mtd></mtr><mtr><mtd><mstyle scriptlevel="0" displaystyle="false"><mn>19</mn></mstyle></mtd><mtd><mstyle scriptlevel="0" displaystyle="false"><mn>10</mn></mstyle></mtd></mtr><mtr><mtd><mstyle scriptlevel="0" displaystyle="false"><mn>11</mn></mstyle></mtd><mtd><mstyle scriptlevel="0" displaystyle="false"><mn>15</mn></mstyle></mtd></mtr></mtable><mo fence="true">]</mo></mrow><annotation encoding="application/x-tex">\begin{bmatrix}
21 &amp; 14 \\
19 &amp; 10 \\
11 &amp; 15 \\
\end{bmatrix}
</annotation></semantics></math>⎣<svg xmlns="http://www.w3.org/2000/svg" width='0.6667em' height='0.016em' style='width:0.6667em' viewBox='0 0 666.67 16' preserveAspectRatio='xMinYMin'><path d='M319 0 H403 V16 H319z M319 0 H403 V16 H319z'/></svg>⎡​211911​141015​⎦<svg xmlns="http://www.w3.org/2000/svg" width='0.6667em' height='0.016em' style='width:0.6667em' viewBox='0 0 666.67 16' preserveAspectRatio='xMinYMin'><path d='M263 0 H347 V16 H263z M263 0 H347 V16 H263z'/></svg>⎤​
What is the output?

For the following matrix:

$$
\begin{bmatrix}
9 & 7 & 8 \\
1 & 3 & 6 \\
5 & 4 & 2 \\
\end{bmatrix}
$$

What is the output?

For the following matrix:
<math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mo fence="true">[</mo><mtable rowspacing="0.16em" columnalign="center center center" columnspacing="1em"><mtr><mtd><mstyle scriptlevel="0" displaystyle="false"><mn>9</mn></mstyle></mtd><mtd><mstyle scriptlevel="0" displaystyle="false"><mn>7</mn></mstyle></mtd><mtd><mstyle scriptlevel="0" displaystyle="false"><mn>8</mn></mstyle></mtd></mtr><mtr><mtd><mstyle scriptlevel="0" displaystyle="false"><mn>1</mn></mstyle></mtd><mtd><mstyle scriptlevel="0" displaystyle="false"><mn>3</mn></mstyle></mtd><mtd><mstyle scriptlevel="0" displaystyle="false"><mn>6</mn></mstyle></mtd></mtr><mtr><mtd><mstyle scriptlevel="0" displaystyle="false"><mn>5</mn></mstyle></mtd><mtd><mstyle scriptlevel="0" displaystyle="false"><mn>4</mn></mstyle></mtd><mtd><mstyle scriptlevel="0" displaystyle="false"><mn>2</mn></mstyle></mtd></mtr></mtable><mo fence="true">]</mo></mrow><annotation encoding="application/x-tex">\begin{bmatrix}
9 &amp; 7 &amp; 8 \\
1 &amp; 3 &amp; 6 \\
5 &amp; 4 &amp; 2 \\
\end{bmatrix}
</annotation></semantics></math>⎣<svg xmlns="http://www.w3.org/2000/svg" width='0.6667em' height='0.016em' style='width:0.6667em' viewBox='0 0 666.67 16' preserveAspectRatio='xMinYMin'><path d='M319 0 H403 V16 H319z M319 0 H403 V16 H319z'/></svg>⎡​915​734​862​⎦<svg xmlns="http://www.w3.org/2000/svg" width='0.6667em' height='0.016em' style='width:0.6667em' viewBox='0 0 666.67 16' preserveAspectRatio='xMinYMin'><path d='M263 0 H347 V16 H263z M263 0 H347 V16 H263z'/></svg>⎤​
What is the output?

For the following matrix:

$$
\begin{bmatrix}
3 & 7 & 8 \\
9 & 11 & 13 \\
15 & 16 & 17 \\
\end{bmatrix}
$$

What is the output?

For the following matrix:
<math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mo fence="true">[</mo><mtable rowspacing="0.16em" columnalign="center center center" columnspacing="1em"><mtr><mtd><mstyle scriptlevel="0" displaystyle="false"><mn>3</mn></mstyle></mtd><mtd><mstyle scriptlevel="0" displaystyle="false"><mn>7</mn></mstyle></mtd><mtd><mstyle scriptlevel="0" displaystyle="false"><mn>8</mn></mstyle></mtd></mtr><mtr><mtd><mstyle scriptlevel="0" displaystyle="false"><mn>9</mn></mstyle></mtd><mtd><mstyle scriptlevel="0" displaystyle="false"><mn>11</mn></mstyle></mtd><mtd><mstyle scriptlevel="0" displaystyle="false"><mn>13</mn></mstyle></mtd></mtr><mtr><mtd><mstyle scriptlevel="0" displaystyle="false"><mn>15</mn></mstyle></mtd><mtd><mstyle scriptlevel="0" displaystyle="false"><mn>16</mn></mstyle></mtd><mtd><mstyle scriptlevel="0" displaystyle="false"><mn>17</mn></mstyle></mtd></mtr></mtable><mo fence="true">]</mo></mrow><annotation encoding="application/x-tex">\begin{bmatrix}
3 &amp; 7 &amp; 8 \\
9 &amp; 11 &amp; 13 \\
15 &amp; 16 &amp; 17 \\
\end{bmatrix}
</annotation></semantics></math>⎣<svg xmlns="http://www.w3.org/2000/svg" width='0.6667em' height='0.016em' style='width:0.6667em' viewBox='0 0 666.67 16' preserveAspectRatio='xMinYMin'><path d='M319 0 H403 V16 H319z M319 0 H403 V16 H319z'/></svg>⎡​3915​71116​81317​⎦<svg xmlns="http://www.w3.org/2000/svg" width='0.6667em' height='0.016em' style='width:0.6667em' viewBox='0 0 666.67 16' preserveAspectRatio='xMinYMin'><path d='M263 0 H347 V16 H263z M263 0 H347 V16 H263z'/></svg>⎤​
What is the output?

Lucky Numbers in a Matrix

Lucky Numbers in a Matrix

# Quick Fix\nYou are Edward, a Senior Software Engineer who specializes in coding interview patterns, data structures and algorithms, and is great at debugging issues in code.\n\n- Edward, please keep in mind that you do not have to print the data of the placeholders. Also, do not mention anything about yourself.\n\nEdward, you are given the following data in the placeholders:\n- Function name: `lucky_numbers`\n- Candidate's submitted solution code: USER_CODE\n- Error: ERROR_DESCRIPTION\n- Failed test case: FAILED_TEST_CASE\n- Coding language: `Python`\n\n- Edward, your task is to understand the type of error that is occurring in the coding language provided.\n- Once you've understood the error as per the error’s description, and why the test case failed, you will suggest how the candidate can improve their solution code to fix the error.\n- Edward, you will not give the corrected code, just a hint on what the error tells, and how to fix it.\n- Edward, please limit your response strictly to 100 words. No more words than the limit.

# Review Code\nEdward, your current task is to review the `lucky_numbers` function(s) and the other function(s) invoked in it/them.\n\n-Take your time and review the candidate's solution code.\n- Do not review any extra/helper files or functions not invoked in the solution function `lucky_numbers`.\n- Do not review the code of data structure objects instantiated like a binary tree, linked list, trie, union find, etc., in the solution functions. Just review the solution/algorithm function of the problem. \n- Also, if the solution code doesn’t use the coding pattern stated above, then please encourage the candidate to reattempt the problem using that pattern corectly.

# Review time complexity\n- Please provide a brief time complexity analysis of the function(s) `lucky_numbers`. \n- While calculating time complexity, include the time complexity of built-in Python functions invoked by the code. \n- The answer should be to the point in approximately 60 words.

# Review space complexity\n- Please provide a brief space complexity analysis of the function(s) `lucky_numbers`. \n- While calculating space complexity, include the space complexity of built-in Python functions invoked by the code. \n- Do not include the space used for the input parameters and the space used for just returning an output (not used as a scratch space). \n- The answer should be to the point in approximately 60 words.

TwoDArray

import sys
import json

sys.path.append("../ds_v1")
from data_structure import DataStructure

# throw parsing errors for incorrect test case format
def parsingError(element_string, error_message):
    sys.stderr.write(f"Parsing Error: {element_string} {error_message}")
    exit()


# className: TwoDArray
class TwoDArray(DataStructure):
    def __init__(self):
        # constructor
        pass

    def __str__(self):
        # override print() for your data structure
        pass

    # return value will be passed to user program
    def construct(self, value: str, type_of_arr: int) -> any:
        # parse test case in json string 'value' to your desired data structure
        return json.loads(value)

    # input param contains return value of user program
    def traverse(self, input: any, type_of_arr: int) -> str:
        # convert your data structure 'input' to a json string representing a test case output
        return json.dumps(input)


def evaluate_results(self) -> object:
        """
        self.__inputs is the list of inputs that are passed as input to function
        self.__actual_output is a list of outputs that is produced by the learner's code
        return : self.__edu__result object
        """
        
        def lucky_numbers_eval(matrix):
            # Get the number of rows (N) and columns (M) in the matrix
            N, M = len(matrix), len(matrix[0])
            r_min_max = float('-inf')
            
            # Loop through each row in the matrix
            for i in range(N):
                # Find the minimum value in the current row
                r_min = min(matrix[i])  
                # Update r_min_max to be the maximum of the current r_min_max and the current row minimum
                r_min_max = max(r_min_max, r_min)
          
            # Initialize variable to keep track of the minimum of the maximum values from each column
            c_max_min = float('inf')
            
            # Loop through each column in the matrix
            for i in range(M):
                # Find the maximum value in the current column
                c_max = max(matrix[j][i] for j in range(N))
                # Update c_max_min to be the minimum of the current c_max_min and the current column maximum
                c_max_min = min(c_max_min, c_max)
          
            # Check if the maximum of row minima is equal to the minimum of column maxima
            if r_min_max == c_max_min:
                # If they are equal, return a list containing the lucky number
                return [r_min_max]
            else:
                # Otherwise, return an empty list indicating no lucky number exists
                return []
                
        
        expected = lucky_numbers_eval(self.__inputs[0])
        actual = self.__actual_outputs[0]
        # multiple outputs will be added at each index respectively for a single test_case
        expected_outputs = []
        # store the 1st expected output that should be displayed to the user 
        expected_outputs.append(expected)

        if json.dumps(expected) == json.dumps(actual):
            self.__edu_result.store_result(expected_outputs, TestCaseResult.PASS)
        else:
            self.__edu_result.store_result(expected_outputs, TestCaseResult.FAIL)

        return self.__edu_result

def lucky_numbers(matrix):
    
      # Replace the following placeholder return statement with your code
      return []


lucky_number_testcases_with_output_9.yaml

testcases:
  - name: "testcase 1"
    inputs:
    - 1 : [[3, 7, 8], [9, 11, 13], [15, 16, 17]]
    output: 
    - 1 : [15]
  - name: "testcase 2"
    inputs:
    - 1: [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
    output:
    - 1 : [7]
  - name: "testcase 3"
    inputs:
    - 1: [[10, 20, 30, 40], [5, 25, 35, 50], [60, 70, 80, 90], [100, 110, 120, 130]]
    output:
    - 1 : [100]
  - name: "testcase 4"
    inputs:
    - 1: [[12, 18, 23, 50], [5, 16, 25, 45], [4, 15, 26, 48], [3, 14, 27, 60]]
    output:
    - 1 : [12]
  - name: "testcase 5"
    inputs:
    - 1: [[5]]
    output:
    - 1 : [5]

def sum(input_1, input_2):
    return input_1+input_2

def validate_inputs(self) -> None:
 """
 Validates the inputs for the lucky number problem.
 Ensures the input is a valid 2D matrix of integers.
 Uses self.store_result(error_msg, status) to report results.
 return: void
 """
 # Access the matrix from inputs
 matrix = self.__inputs[0]
 
 # Function to check whether valid 2D array of integers or not
 def valid_2D(arr):
 if not isinstance(arr, list) or not arr: # Check if arr is a non-empty list
 return False
 for row in arr:
 if not isinstance(row, list): # Check if each row is a list
 return False
 for element in row:
 if not isinstance(element, int): # Ensure elements are integers
 return False
 return True
 
 # Check None in input
 if matrix is None:
 self.store_result("Input cannot be None.", ValidationFunction.FAIL)
 return
 
 # Validate the matrix structure
 if not valid_2D(matrix):
 self.store_result("Input must be a valid 2D array of integers.", ValidationFunction.FAIL)
 return
 
 # Check for empty matrices or invalid structures like [[]]
 if len(matrix) == 0 or (len(matrix) == 1 and len(matrix[0]) == 0):
 self.store_result("Matrix cannot be empty or [[]].", ValidationFunction.FAIL)
 return
 
 # Validate matrix dimensions
 m, n = len(matrix), len(matrix[0])
 if m > 50 or n > 50:
 self.store_result("Matrix dimensions (m, n) must not exceed 50.", ValidationFunction.FAIL)
 return
 
 # Check if all rows have the same number of columns
 for row in matrix:
 if len(row) != n:
 self.store_result("All rows in the matrix must have the same length.", ValidationFunction.FAIL)
 return
 
 # Validate matrix elements
 seen_elements = set()
 for row in matrix:
 for element in row:
 if not (1 <= element <= 10**5): # Check element range
 self.store_result("Matrix elements must be between 1 and 10^5.", ValidationFunction.FAIL)
 return
 if element in seen_elements: # Check for distinct elements
 self.store_result("Matrix elements must be distinct.", ValidationFunction.FAIL)
 return
 seen_elements.add(element)
 
 # If all validations pass
 self.store_result("", ValidationFunction.PASS)

Try to solve the Lucky Numbers in a Matrix problem.

Problem: Lucky Numbers in a Matrix

Statement

Examples

Understand the problem

Figure it out!