Intervals & Overlaps · Medium

Merge Intervals

O(N log N) · O(N)

Step 1: Setup & Initialization - Merge Intervals

Sort intervals by start time and extend bounds if overlap occurs.

Array Elements & Pointers
10
[0]
20
[1]
30
[2]
40
[3]
50
[4]
Live Variables & Invariants
status:Initialized
pattern:Merge Intervals
Step 1 / 3
33%
Solution Code
1
function merge(intervals: number[][]): number[][] {
2
  intervals.sort((a, b) => a[0] - b[0]);
3
  const res: number[][] = [intervals[0]];
4
  for (let i = 1; i < intervals.length; i++) {
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    const last = res[res.length - 1];
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    if (intervals[i][0] <= last[1]) last[1] = Math.max(last[1], intervals[i][1]);
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    else res.push(intervals[i]);
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  }
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  return res;
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}
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Test Cases

3 cases from Blind 75 & NeetCode 150

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