How do you solve Goal Parser Interpretation on LeetCode?

Goal Parser Interpretation (LeetCode #1678) can be solved using Brute Force or Optimal Solution. The optimal approach is Optimal Solution with O(n) time complexity and O(n) space complexity. Key insight: Understanding how to interpret substrings is crucial for string manipulation problems.

What is the brute force solution for Goal Parser Interpretation?

The brute force approach for Goal Parser Interpretation is Brute Force, with O(n²) time complexity and O(1) space complexity. The brute force approach involves iterating through the string character by character and checking for specific patterns. Whenever we encounter 'G', '()', or '(al)', we append the corresponding interpretation to a result string. The optimal Optimal Solution approach improves this to O(n).

What algorithm or data structure is used to solve Goal Parser Interpretation?

Goal Parser Interpretation uses the following concepts: String. The recommended patterns to study are: String Manipulation, Pattern Recognition.

What are the interview tips for Goal Parser Interpretation?

Always clarify the problem statement and constraints before diving into coding. Think aloud while coding to demonstrate your thought process to the interviewer. Test your solution with edge cases to ensure robustness.

What are common mistakes when solving Goal Parser Interpretation?

Not checking the correct lengths of substrings, leading to index out of bounds errors. Overcomplicating the logic by using unnecessary nested loops.

#1678

Goal Parser Interpretation

Easy

StringString ManipulationPattern Recognition

LeetCode ↗

Approaches

Brute ForceOptimal

Complexity Comparison

	Brute Force	Optimal Solution★
Time	O(n²)	O(n)
Space	O(1)	O(n)

💡

Intuition

Time O(n)Space O(n)

The optimal solution uses a single pass through the string while checking for specific patterns. This avoids the need for substring checks, making it more efficient.

⚙️

Algorithm

3 steps

1Step 1: Initialize an empty result string.
2Step 2: Use a single loop to iterate through the command string.
3Step 3: Append 'G', 'o', or 'al' to the result based on the current character and the next characters.

solution.py15 lines

1def interpret(command):
2    result = ''
3    i = 0
4    while i < len(command):
5        if command[i] == 'G':
6            result += 'G'
7            i += 1
8        elif command[i] == '(':  # Check for '('
9            if command[i + 1] == ')':
10                result += 'o'
11                i += 2
12            else:
13                result += 'al'
14                i += 4
15    return result

ℹ

Complexity note: The time complexity is O(n) because we only pass through the string once. The space complexity is O(n) due to the result string being built.

1Understanding how to interpret substrings is crucial for string manipulation problems.
2Recognizing patterns in the input can help optimize your approach.

Solutions and explanations are original Tejav content. Problem titles © LeetCode — use the LeetCode button above for the full problem statement.