DAY 53 Sliding Window Meets Prefix Sum: Elevating Problem Solving

Hello everyone!

Day 3 of Week 11 introduces a series of sliding window and prefix sum techniques, which are two powerful tools for optimizing array problems. Today’s tasks require tracking accumulated data and leveraging it for effective decision-making. It feels like sailing through a dynamic landscape, adjusting and optimizing along the way.

How did the day go?

1. Find the highest altitude (easy difficulty)

   • Given a set of gain values, calculate the highest altitude reached during the journey.
   • Strategy:
     • Use the prefix sum method to track the cumulative height of each step.
     • Maintain running max to determine maximum altitude.
   • The interesting part:
     • Watching the altitude dynamically rise and fall with each gain value feels like you’re on a true journey through peaks and valleys.

2. Finding Pivot Index (Easy Difficulty)

   • Finds the pivot index of the array where the sum of the elements on the left is equal to the sum of the elements on the right.
   • Strategy:
     • Calculate the sum of the array and iterate over it, keeping the left sum running.
     • At each index, check whether the left sum is equal to the sum minus the current element and the left sum.
   • The interesting part:
     • Finding the balance is like balancing the seesaw perfectly – it pays to see the logical consistency.

what makes today special

1. Prefix total power:

   • Both problems demonstrate the efficiency of prefix sums in tracking cumulative information for fast calculations.

2. Optimize through clarity:

   • Tasks such as Find pivot index Emphasizes the importance of breaking down problems into logical components to achieve elegant solutions.

3. Visual dynamics:

   • Tracking height changes and equilibrium points makes the problem intuitive and engaging, adding a layer of practical understanding.

focus

Reflection

this Find the highest altitude The problem is a simple but satisfying application of prefix sums, while Find pivot index Its equilibrium conditions add a layer of complexity. Together, these tasks emphasize the importance of cumulative data tracking and logical problem decomposition in solving array challenges.

What’s next?

I will solve it tomorrow Hashmap/set probleminclude Find the difference between two arrays and unique occurrences. These tasks will test my ability to utilize hash-based structures for efficient data management.

Thank you for your attention! Let’s keep solving, learning, and growing together.