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Help us understand the problem. What is going on with this article?
@narutaro

# LeetCode - 56. Merge Intervals

More than 1 year has passed since last update.

# 問題

56. Merge Intervals

# Ver. 1

1. とりあえず `interval``merged_intervals` にほりこむ
2. `merged_intervals` の最後の要素 `[a, b]` を取り出して、次の `interval``[x, y]` と重なっているか判定
3. `interval` が重なってなかったら、`[a, b]`, `[x, y]` をそのまま`merged_intervals` にほりこむ
4. 重なってたら、`[a, b]`, `[x, y]` をマージしてほりこむ
• `intervals` は事前にソートされていないとうまくいかない
• `O(n^2)` を避けるため、ソートして、都度マージする
```# @param {Integer[][]} intervals
# @return {Integer[][]}
def merge(intervals)
merged_intervals = []

intervals.sort.each do |curr|
last = merged_intervals.pop
if last.nil?
merged_intervals << curr
elsif last[1] < curr[0] || curr[1] < last[0] # Last and curret are not overlapped
merged_intervals << last << curr
else # Last and curret are overlapped
merged_intervals << [(last + curr).min, (last + curr).max]
end
end

merged_intervals
end
```

# スコア

```Runtime: 88 ms, faster than 15.18% of Ruby online submissions for Merge Intervals.
Memory Usage: 9.8 MB, less than 100.00% of Ruby online submissions for Merge Intervals.
```

いまいち...

# Ver. 2

コメントいただいて、再度考えてみたバージョン

```# @param {Integer[][]} intervals
# @return {Integer[][]}
def merge(intervals)
merged_intervals = []

intervals.sort.each do |curr|
last = merged_intervals.last
if last.nil?
merged_intervals << curr
elsif last[1] < curr[0]  # Last and curret are NOT overlapped
merged_intervals << curr
else # Last and curret are overlapped
last[1] = (last + curr).max
end
end

merged_intervals
end
```

# スコア

```Runtime: 60 ms, faster than 44.64% of Ruby online submissions for Merge Intervals.
Memory Usage: 9.7 MB, less than 100.00% of Ruby online submissions for Merge Intervals.
```

だいぶよくなった

0
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