Hurdle Jump in JavaScript

Given an array of hurdle heights and a jumper's jump height, determine whether or not the hurdler can clear all the hurdles. If they can, return true; otherwise return false.

A hurdler can clear a hurdle if their jump height is greater than or equal to the hurdle height.

Examples:

hurdleJump([1, 2, 3, 4, 5], 5) ➞ true

hurdleJump([5, 5, 3, 4, 5], 3) ➞ false

hurdleJump([5, 4, 5, 6], 10) ➞ true

hurdleJump([1, 2, 1], 1) ➞ false

Note: Return true for the edge case of an empty array of hurdles. (Zero hurdles means that any jump height can clear them).

Understanding the Problem

The core challenge of this problem is to determine if the jumper's height is sufficient to clear all the hurdles in the array. This problem is significant in scenarios where we need to check if a certain threshold is met across a series of values, which is a common requirement in various applications such as gaming, sports analytics, and more.

Potential pitfalls include not handling the edge case of an empty array correctly and misunderstanding the requirement that the jump height must be greater than or equal to each hurdle height.

Approach

To solve this problem, we can follow these steps:

Check if the array of hurdles is empty. If it is, return true immediately.
Iterate through the array of hurdles and compare each hurdle height with the jumper's jump height.
If any hurdle height is greater than the jumper's jump height, return false.
If the loop completes without finding any hurdle that the jumper cannot clear, return true.

Naive Solution

A naive solution would involve iterating through the array and checking each hurdle height against the jump height. This approach is straightforward but not necessarily inefficient for this problem since it only requires a single pass through the array.

Optimized Solution

The optimized solution is essentially the same as the naive solution because the problem is simple enough that a single pass through the array (O(n) time complexity) is optimal. We can further optimize by returning early if we find a hurdle that the jumper cannot clear.

Algorithm

Here is a step-by-step breakdown of the algorithm:

Check if the array of hurdles is empty. If it is, return true.
Iterate through each hurdle in the array.
For each hurdle, check if the jumper's jump height is less than the hurdle height.
If a hurdle is found that the jumper cannot clear, return false immediately.
If the loop completes without finding any such hurdle, return true.

Code Implementation

function hurdleJump(hurdles, jumpHeight) {
  // Edge case: if there are no hurdles, return true
  if (hurdles.length === 0) {
    return true;
  }

  // Iterate through each hurdle
  for (let i = 0; i < hurdles.length; i++) {
    // If the jump height is less than the hurdle height, return false
    if (jumpHeight < hurdles[i]) {
      return false;
    }
  }

  // If all hurdles can be cleared, return true
  return true;
}

// Test cases
console.log(hurdleJump([1, 2, 3, 4, 5], 5)); // ➞ true
console.log(hurdleJump([5, 5, 3, 4, 5], 3)); // ➞ false
console.log(hurdleJump([5, 4, 5, 6], 10)); // ➞ true
console.log(hurdleJump([1, 2, 1], 1)); // ➞ false
console.log(hurdleJump([], 1)); // ➞ true

Complexity Analysis

The time complexity of this solution is O(n), where n is the number of hurdles. This is because we need to check each hurdle once. The space complexity is O(1) since we are not using any additional space that scales with the input size.

Edge Cases

Potential edge cases include:

An empty array of hurdles: The function should return true.
All hurdles being the same height as the jump height: The function should return true.
All hurdles being higher than the jump height: The function should return false.

Examples of edge cases and their expected outputs:

hurdleJump([], 1) ➞ true
hurdleJump([3, 3, 3], 3) ➞ true
hurdleJump([4, 5, 6], 3) ➞ false

Testing

To test the solution comprehensively, we should include a variety of test cases:

Simple cases with a few hurdles.
Cases where the jump height is exactly equal to the highest hurdle.
Cases where the jump height is less than the highest hurdle.
Edge cases such as an empty array of hurdles.

We can use JavaScript's built-in console.log for simple testing, or frameworks like Jest for more comprehensive testing.

Thinking and Problem-Solving Tips

When approaching such problems, it's important to:

Understand the problem requirements and constraints thoroughly.
Consider edge cases and how they should be handled.
Start with a simple, naive solution and then look for optimizations.
Write clean, readable code with comments to explain your thought process.

To improve problem-solving skills, practice regularly with similar problems, study different algorithms, and understand their trade-offs.

Conclusion

In this blog post, we discussed how to determine if a jumper can clear all hurdles given their heights and the jumper's jump height. We covered the problem definition, approach, algorithm, code implementation, complexity analysis, edge cases, and testing. Understanding and solving such problems is crucial for developing strong problem-solving skills and algorithmic thinking.

We encourage readers to practice and explore further to solidify their understanding.

Additional Resources

For further reading and practice problems, consider the following resources:

LeetCode - A platform for practicing coding problems.
HackerRank - Another platform for coding challenges and competitions.
Eloquent JavaScript - A book that covers JavaScript and programming concepts in depth.
MDN Web Docs - Comprehensive documentation on JavaScript.

Hurdle Jump in JavaScript (Time Complexity: O(n))