DAY 48 Arrays and Strings: Relationships and Constraints

Hello Everyone!

Day 3 of Week 10 delved into more intricate Array and String problems. These tasks focused on identifying relationships between elements and handling constraints efficiently. Solving them felt like piecing together a puzzle, where each part had to fit perfectly within the larger picture.

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How the Day Played Out

1. Product of Array Except Self (Medium Difficulty)

   • Compute an array where each element is the product of all other elements except itself, without using division.
   • The Strategy:
     • Used two passes:
     • First pass: Calculated the prefix product for each element.
     • Second pass: Combined prefix products with suffix products iteratively, using a single variable for the suffix.
     • Avoided using division, ensuring the solution was efficient and adhered to the constraints.
   • The Fun Part:
     • Watching the final array build up dynamically felt like constructing a masterpiece layer by layer.

2. Increasing Triplet Subsequence (Medium Difficulty)

   • Determine if there exists an increasing subsequence of length 3 in the array.
   • The Strategy:
     • Maintained two variables (first and second) to track the smallest and second smallest elements encountered.
     • Identified a third element larger than second to confirm the increasing triplet condition.
   • The Fun Part:
     • Tracking the sequence dynamically and watching the conditions align felt like solving a live logic puzzle.

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What Made Today Special

1. Dynamic Problem-Solving:

   • Both tasks required real-time updates to variables or arrays, emphasizing adaptability and precision in the approach.

2. Efficiency through Simplicity:

   • Avoiding nested loops and division in Product of Array Except Self highlighted how simplicity often leads to optimal solutions.

3. Tracking Relationships:

   • Identifying patterns, like increasing sequences in Increasing Triplet Subsequence, demonstrated the importance of observing relationships between elements.

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Key Takeaways

• Prefix and Suffix Products Simplify Computations:

  • Problems like Product of Array Except Self show how combining partial results in multiple passes avoids unnecessary complexity.

• Single Pass Tracking is Powerful:

  • Maintaining variables dynamically, as in Increasing Triplet Subsequence, ensures efficiency while adhering to constraints.

• Think in Layers:

  • Both problems benefited from breaking the solution into logical steps, building results layer by layer.

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Reflections

The Product of Array Except Self problem was a rewarding exercise in optimization, while Increasing Triplet Subsequence added a layer of complexity with its dynamic conditions. Together, these challenges emphasized the importance of efficient algorithms and careful observation in solving array problems.

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What’s Next?

On Monday, I’ll conclude Week 10 with Arrays and Strings, Two-Pointer Problems, tackling String Compression and Move Zeroes. These tasks will combine compression techniques with efficient element management for elegant solutions.

Thank you for following along! Let’s keep solving, learning, and growing together.