What is the time complexity of Shortest Distance to Target String in a Circular Array?

The optimal solution for Shortest Distance to Target String in a Circular Array runs in O(n) time and uses O(1) space. The time complexity is O(n) because we make a single pass through the array to find the target and calculate distances, which is efficient for this problem.

What is the brute force solution for Shortest Distance to Target String in a Circular Array?

The brute force approach for Shortest Distance to Target String in a Circular Array is Brute Force, with O(n²) time complexity and O(1) space complexity. The brute force approach involves checking every possible position in the circular array to find the target string. We calculate the distance from the start index to each occurrence of the target, both clockwise and counterclockwise, and then return the minimum distance found. The optimal Optimal Solution approach improves this to O(n).

What algorithm or data structure is used to solve Shortest Distance to Target String in a Circular Array?

Shortest Distance to Target String in a Circular Array uses the following concepts: Array, String. The recommended patterns to study are: Circular Array, Two Pointers.

What are the interview tips for Shortest Distance to Target String in a Circular Array?

Always clarify the problem requirements and constraints before diving into coding. Think about edge cases, like when the target is not present in the array. Use meaningful variable names to make your code easier to read and understand.

What are common mistakes when solving Shortest Distance to Target String in a Circular Array?

Forgetting to account for the circular nature of the array when calculating distances. Not checking if the target exists in the array before calculating distances.

#2515

Shortest Distance to Target String in a Circular Array

Easy

ArrayStringCircular ArrayTwo Pointers

LeetCode ↗

Approaches

Brute ForceOptimal

Complexity Comparison

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

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Intuition

Time O(n)Space O(1)

The optimal solution involves a single pass through the array to find all occurrences of the target string. By calculating the distances in both directions (clockwise and counterclockwise) simultaneously, we can determine the shortest distance efficiently.

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Algorithm

5 steps

1Step 1: Initialize a variable to store the minimum distance as infinity.
2Step 2: Create a loop to iterate through the circular array and find all occurrences of the target string.
3Step 3: For each occurrence, calculate the distance to the startIndex in both directions.
4Step 4: Update the minimum distance if the calculated distance is smaller.
5Step 5: Return the minimum distance or -1 if the target is not found.

solution.py10 lines

1# Full working Python code
2
3def shortestDistance(words, target, startIndex):
4    min_distance = float('inf')
5    n = len(words)
6    for i in range(n):
7        if words[i] == target:
8            distance = min((i - startIndex) % n, (startIndex - i) % n)
9            min_distance = min(min_distance, distance)
10    return min_distance if min_distance != float('inf') else -1

ℹ

Complexity note: The time complexity is O(n) because we make a single pass through the array to find the target and calculate distances, which is efficient for this problem.

1The circular nature of the array allows for two potential paths to the target.
2Calculating distances in both directions is crucial for finding the shortest path.

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