Скачать или смотреть LeetCode | Count Partitions with Even Sum Difference | C++ | Golang | Rust

In this video we solve LeetCode 3432. Count Partitions with Even Sum Difference (daily challenge).
I start from the definition of a partition, write the prefix and suffix sums, and then use a small algebra + parity trick to simplify the condition:

diff=pref−suff=2⋅pref−total

From here we see that the difference is even iff the total sum of the array is even, which means either all partitions work or none of them do. I walk through this step-by-step using the drawings in the video so you clearly see why the answer is either n - 1 or 0.

After the intuition, I implement the final O(n) / O(1) solution in C++, Golang, and Rust, explaining the small implementation details in each language. This is a neat example of how a math observation can completely kill the need for heavy prefix-sum logic and is great practice for coding interviews and LeetCode daily problems.

⏱ Timestamps

00:00 – Problem Statement and Logic
07:02 – C++ Implementation
07:41 – Golang Implementation
08:15 – Rust Implementation