AoC 2021 D1: Sonar Sweep

| Problem statement | Source code | Tags: Brute forceMathematics

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Part 1

Just iterate through the list and count the number of times the current number is larger than the previous one: nums[i-1] < nums[i]. Because there needs to be a previous number to compare to, we start from the second number.

Part 2

No need to actually build the sliding windows. If nums[i] + nums[i-1] + nums[i-2] < nums[i+1] + nums[i] + nums[i-1], then nums[i-2] < nums[i+1]. Therefore we can use the same logic as part 1, but compare nums[i] with nums[i-3], so i starts from 3.

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