How do you solve Check if Word Equals Summation of Two Words on LeetCode?

Check if Word Equals Summation of Two Words (LeetCode #1880) can be solved using Brute Force or Optimal Solution. The optimal approach is Optimal Solution with O(n) time complexity and O(1) space complexity. Key insight: Understanding how to convert characters to their numerical values is crucial.

What is the brute force solution for Check if Word Equals Summation of Two Words?

The brute force approach for Check if Word Equals Summation of Two Words is Brute Force, with O(n²) time complexity and O(1) space complexity. We can calculate the numerical values of each word by converting each character to its corresponding integer value based on its position in the alphabet. Then, we can check if the sum of the first two words equals the third word's value. The optimal Optimal Solution approach improves this to O(n).

What algorithm or data structure is used to solve Check if Word Equals Summation of Two Words?

Check if Word Equals Summation of Two Words uses the following concepts: String. The recommended patterns to study are: String Manipulation, Mathematical Operations.

What are the interview tips for Check if Word Equals Summation of Two Words?

Always clarify the problem statement and constraints before diving into coding. Think about both brute force and optimal solutions; interviewers appreciate seeing both. Discuss your thought process and reasoning as you code.

What are common mistakes when solving Check if Word Equals Summation of Two Words?

Overcomplicating the conversion process by using strings instead of direct calculations. Not considering edge cases like empty strings.

#1880

Check if Word Equals Summation of Two Words

Easy

StringString ManipulationMathematical Operations

LeetCode ↗

Approaches

Brute ForceOptimal

Complexity Comparison

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

💡

Intuition

Time O(n)Space O(1)

Instead of converting the entire string to an integer, we can calculate the numerical values directly while iterating through the characters. This avoids the overhead of string manipulation and conversion.

⚙️

Algorithm

4 steps

1Step 1: Initialize two sums for firstWord and secondWord.
2Step 2: Iterate through each character of both words simultaneously, calculating their respective numerical values.
3Step 3: Calculate the numerical value of targetWord in a similar manner.
4Step 4: Return true if the sum of the first two equals the value of targetWord.

solution.py9 lines

1# Full working Python code
2
3def is_sum_equal(firstWord, secondWord, targetWord):
4    def calculate_value(word):
5        total = 0
6        for c in word:
7            total = total * 10 + (ord(c) - ord('a'))
8        return total
9    return calculate_value(firstWord) + calculate_value(secondWord) == calculate_value(targetWord)

ℹ

Complexity note: The time complexity is O(n) because we are iterating through each character of the words only once to compute their values, which is more efficient than the brute force method.

1Understanding how to convert characters to their numerical values is crucial.
2Efficiently calculating values without unnecessary conversions can save time.

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