LeetCode-in-All

56. Merge Intervals

Medium

Given an array of intervals where intervals[i] = [starti, endi], merge all overlapping intervals, and return an array of the non-overlapping intervals that cover all the intervals in the input.

Example 1:

Input: intervals = [[1,3],[2,6],[8,10],[15,18]]

Output: [[1,6],[8,10],[15,18]]

Explanation: Since intervals [1,3] and [2,6] overlap, merge them into [1,6].

Example 2:

Input: intervals = [[1,4],[4,5]]

Output: [[1,5]]

Explanation: Intervals [1,4] and [4,5] are considered overlapping.

Constraints:

• 1 <= intervals.length <= 104
• intervals[i].length == 2
• 0 <= starti <= endi <= 104

Solution

impl Solution {
    pub fn merge(intervals: Vec<Vec<i32>>) -> Vec<Vec<i32>> {
        // Sort the intervals by the start value
        let mut intervals = intervals;
        intervals.sort_by(|a, b| a[0].cmp(&b[0]));

        let mut merged: Vec<Vec<i32>> = Vec::new();
        let mut current = intervals[0].clone();
        merged.push(current.clone());

        for next in intervals.into_iter().skip(1) {
            if current[1] >= next[0] {
                current[1] = current[1].max(next[1]);
                if let Some(last) = merged.last_mut() {
                    last[1] = current[1];
                }
            } else {
                current = next.clone();
                merged.push(current.clone());
            }
        }

        merged
    }
}

This site is open source. Improve this page.