Learn and practice the Sliding Window, and Union Find patterns to solve coding interview problems.

Speedrun the Oracle Coding Interview: Top Problems in Go

Each pattern in this module exemplifies the power of dissecting a problem in detail and figuring out the least expensive operations required to solve it. In the Sliding Window pattern, we’ll gain practice in various techniques to ensure that a solution that seems to require nested loops actually executes in linear time. Using the Union Find pattern, we’ll learn to solve a diverse set of problems using the disjoint-set data structure.

Elegant by Design

What should be the output if the following prices are given as an input?

prices = [10, 4, 11, 1, 5]


What should be the output if the following prices are given as an input?
prices = [10, 4, 11, 1, 5]

What should be the output if the following prices are given as an input?


 prices = [7, 7, 6, 6, 6]

What should be the output if the following prices are given as an input?
prices = [7, 7, 6, 6, 6]

What should be the output if the following prices are given as an input?

prices = [4, 10, 5, 1, 6, 7]

What should be the output if the following prices are given as an input?
prices = [4, 10, 5, 1, 6, 7]

What should be the output if the following prices are given as an input?

prices = [4, 4, 4, 3, 3, 4]

What should be the output if the following prices are given as an input?
prices = [4, 4, 4, 3, 3, 4]

Best Time to Buy and Sell Stock

Best Time to Buy and Sell Stock

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

> **Note:** As an additional challenge, we have intentionally hidden the solution to this puzzle.


Implement your solution in the following coding playground. 

Help me debug only the function Best Time to Buy and Sell Stock . . 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 maxProfit function and the other function(s) invoked in it/them. Do not review extra/helper files or functions not invoked in the solution function maxProfit. 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 Greedy Techniques pattern used? Take your time and review the code.

Please provide a brief time complexity analysis of the function maxProfit. While calculating time complexity, include the time complexity of built-in Go 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 maxProfit. While calculating space complexity, include the space complexity of built-in Go 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

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 max_profit1(prices):
 buy = 0
 sell = 1 
 maxprofit = 0

 while sell < len(prices):
 currentprofit = prices[sell] - prices[buy]
 if prices[buy] < prices[sell]:
 maxprofit = max(currentprofit, maxprofit)
 else:
 buy = sell
 
 sell += 1
 
 return maxprofit

 def compareResult(expected, actual_output): 
 if expected == actual_output:
 return True
 return False


 # 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 = max_profit1(self.__inputs[0])
 expected_outputs.append(expected)
 actual_output = self.__actual_outputs[0]

 compare = compareResult(expected, actual_output)
 if compare:
 self.__edu_result.store_result(expected_outputs, TestCaseResult.PASS)
 else:
 self.__edu_result.store_result(expected_outputs, TestCaseResult.FAIL)

 return self.__edu_result

package main

func maxProfit(prices []int) int {

    // Replace this placeholder return statement with your code
    
    return -1
}

best-time-buy-sell.yaml

testcases:
  - name: "testcase 1"
    inputs:
    - 1 : [1, 2, 4, 2, 5, 7, 2, 4, 9, 0, 9]
    output: 
    - 1 : 9
  - name: "testcase 2"
    inputs:
    - 1: [7, 1, 5, 3, 6, 4]
    output:
    - 1 : 5
  - name: "testcase 3"
    inputs:
    - 1:  [7, 6, 4, 3, 1]
    output:
    - 1: 0
  - name: "testcase 4"
    inputs:
    - 1: [2, 6, 8, 7, 8, 7, 9, 4, 1, 2, 4, 5, 8]
    output:
    - 1: 7
  - name: "testcase 5"
    inputs:
    - 1: [1, 4, 2]
    output:
    - 1: 3

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 function
 store the result using the self.store_result(error_msg, status)
 return : void
 """
 inp = self.__inputs[0]
 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(inp):
 self.store_result ("Invalid 1D array", ValidationFunction.FAIL)

 elif not isinstance(inp, list):
 self.store_result ("Expected integer array", ValidationFunction.FAIL)


 elif any(num is None for num in inp):
 self.store_result ("Array should not contain null values", ValidationFunction.FAIL)
 # inputs can be accessed using self.__inputs starting from 0 to len(self.__inputs) - 1
 elif len(self.__inputs[0]) < 1 or len(self.__inputs[0]) > 1000:
 self.store_result ("Length of the array should be in range [1, 1000]", ValidationFunction.FAIL)
 # elif any(self.__inputs[0][i] < 0 or self.__inputs[0][i] > 100000 for i in self.__inputs[0]):
 elif any(x < 0 or x > 100000 for x in self.__inputs[0]):
 self.store_result("Element of an array should be in range [0, 100000]", ValidationFunction.FAIL)
 else:
 self.store_result("", ValidationFunction.PASS)

Try to solve the Best Time to Buy and Sell Stock problem.

Sliding Window

Union Find

Conclusion

Best Time to Buy and Sell Stock

Statement

Examples

Understand the problem

Figure it out!

Try it yourself