Learn and practice the Cyclic Sort and Topological Sort patterns to solve coding interview problems.

Educative-99 in Java: Accelerate Your Coding Interview Prep

This module will focus on two advanced sorting algorithms, Cyclic Sort and Topological Sort. These are often used in coding interviews as a way to distinguish between average and outstanding candidates. Cyclic Sort may only be used if the input list meets certain criteria, and in those situations, it’s the most efficient sorting algorithm possible. Topological Sort utilizes graph-based algorithms to deal with partially ordered elements. This module teaches us to recognize whether either of these advanced sorting techniques is applicable, as well as how to use them to solve the given problem.

Advanced Sorting Techniques

# Statement
We are given an unsorted array, `nums`, with $n$ elements and each element is in the range $[1, n]$ inclusive. The array originally contained all the elements from $1$ to $n$ but due to a data error, one of the numbers is duplicated, which causes another number missing. Find and return the corrupt pair (missing, duplicated).

**Constraints:**
- $2 \leq n \leq 10^3$
- $1 \leq$ `nums[i]` $\leq n$
# Examples

# Understand the problem
Let’s take a moment to make sure you’ve correctly understood the problem. The quiz below helps you check if you’re solving the correct problem:

Which is the corrupt pair in the array given below?

[4, 1, 3, 4, 5]

Which is the corrupt pair in the array given below?
[4, 1, 3, 4, 5]

Which is the corrupt pair in the array given below?

[6, 1, 2, 4, 5, 5]

Which is the corrupt pair in the array given below?
[6, 1, 2, 4, 5, 5]

Which is the corrupt pair in the array given below?

[8, 1, 2, 3, 4, 3, 6, 7]

Which is the corrupt pair in the array given below?
[8, 1, 2, 3, 4, 3, 6, 7]

Find the Corrupt Pair

Find the Corrupt Pair

# Figure it out!
We have a game for you to play. Rearrange the logical building blocks to develop a clearer understanding of how to solve this problem.


# Try it yourself
Implement your solution in the following coding playground:

import java.util.*;
public class FindCorruptPair{
   public static int[] findCorruptPair(int[] nums) {
      
      // Replace this placeholder return statement with your code
      return new int[]{0, 0};
   }
}

Help me debug only the function Find the Corrupt Pair . . I don't need the corrected code.I don't want explanations or code review. Just provide me the exact and to-the-point error that helps me run the code successfully on the test cases provided.

Please help me understand why this code failed for the last failed test case. Don't give me the corrected code. . If yes, then Just provide me the exact and to-the-point error that helps me run the code successfully on the test cases provided.

Your current task is to review only the findCorruptPair function and the other function(s) invoked in it/them. Do not review extra/helper files or functions not invoked in the solution function findCorruptPair. Do not review the code of data structures 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. Also, Answer the following questions: Is the Cyclic Sort pattern used? Take your time and review the code.

Please provide a brief time complexity analysis of the function findCorruptPair. While calculating time complexity, include the time complexity of built-in Java functions invoked by the code. The Answer should be to the point and in a few lines.

Please provide a brief Space complexity analysis of the function findCorruptPair. While calculating space complexity, include the space complexity of built-in Java functions invoked by the code. 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). The Answer should be to the point and in a few lines

OneDArray

import ds_v1.DataStructure.DataStructure;
import java.util.Arrays;
import java.io.IOException;
import com.fasterxml.jackson.databind.ObjectMapper;
public class OneDArray extends DataStructure {
    int[] values = {};


    public OneDArray() {
        //values = {};
    }
    

    public OneDArray(int[] val){
        this.values = val.clone();
        
    }

    public String toString() {
        return Arrays.toString(values);
    }

    @Override
    public OneDArray construct(String new_value, Integer type_of_ds) {
        int[] array={};
        try {
            ObjectMapper mapper = new ObjectMapper();
            array = mapper.readValue(new_value, int[].class);
            
        } catch (IOException e) {
            e.printStackTrace();
        }
        return new OneDArray(array);

    }

    @Override
    public String traverse(Object input, Integer type_of_ds) {
        
        return input.toString();
    }

}

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
 """
 # 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(find_corrupt_pair(self.__inputs[0]))

 if json.dumps(find_corrupt_pair(self.__inputs[0])) == json.dumps(self.__actual_outputs[0]):
 self.__edu_result.store_result(expected_outputs, TestCaseResult.PASS)
 else:
 self.__edu_result.store_result(expected_outputs, TestCaseResult.FAIL)

 return self.__edu_result
def find_corrupt_pair(nums):
 missing = None
 duplicated = None

 def swap(arr, first, second):
 arr[first], arr[second] = arr[second], arr[first]

 i = 0
 while i < len(nums):
 correct = nums[i] - 1
 if nums[i] != nums[correct]:
 swap(nums, i, correct)
 else:
 i += 1

 for j in range(len(nums)):
 if nums[j] != j + 1:
 duplicated = nums[j]
 missing = j + 1

 return missing, duplicated

import java.util.*;
public class Main{
 public static OneDArray findCorruptPair1(OneDArray c) {
    OneDArray s= new OneDArray();
    s.values  =  FindCorruptPair.findCorruptPair(c.values);
    return s;
    
      
 }
}

PrivateTestCases.yaml

testcases:
  - name: "testcase 1"
    inputs:
    - 1 : [3, 1, 2, 5, 2]
    output: 
    - 1 : [4, 2]
  - name: "testcase 2"
    inputs:
    - 1: [3, 1, 2, 3, 6, 4]
    output:
    - 1 : [5, 3]
  - name: "testcase 3"
    inputs:
    - 1: [4, 1, 2, 1, 6, 3]
    output:
    - 1: [5, 1]
  - name: "testcase 4"
    inputs:
    - 1: [4, 3, 4, 5, 1]
    output:
    - 1 : [2, 4]
  - name: "testcase 5"
    inputs:
    - 1: [5, 3, 5, 6, 2, 1]
    output:
    - 1 : [4, 5]

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

def validate_inputs(self) -> None:
 """
 self.__inputs is the list of inputs that are passed as input to the function
 store the result using the self.store_result(error_msg, status)
 return: void
 """
 nums = self.__inputs[0] #self.__inputs[0] contains the list of nums
 def is_valid_1d_array(arr):
 if not isinstance(arr, list):
 return False # Not a valid 1D array if it's not a list
 
 return all(isinstance(elem, int) and not isinstance(elem, bool) for elem in arr)
 if not is_valid_1d_array(nums):
 self.store_result(("Invalid test case."), ValidationFunction.FAIL)

 if any(num is None for num in nums):
 self.store_result ("Not a valid test case", ValidationFunction.FAIL)
 elif len(nums) < 2 or len(nums) > 10**3:
 self.store_result("The length of 'nums' should be between 2 and 10^3", ValidationFunction.FAIL)
 # Check if each element in nums is within the range [1, n]
 elif any(value < 1 or value > len(nums) for value in nums):
 self.store_result("All elements in 'nums' should be between 1 and n", ValidationFunction.FAIL)

 elif len(self.__inputs[0]) != len(set(self.__inputs[0])) + 1:
 self.store_result("Input should have one duplicate number", ValidationFunction.FAIL)

 else:
 self.store_result("", ValidationFunction.PASS)

Try to solve the Find the Corrupt Pair problem.

Cyclic Sort

Topological Sort

Conclusion

Find the Corrupt Pair

Statement

Examples

Understand the problem

Figure it out!

Try it yourself