LeetcodeApr 16, 2026

Non-overlapping Intervals

Hazrat Ali

Leetcode

Given an array of intervals intervals where intervals[i] = [starti, endi], return the minimum number of intervals you need to remove to make the rest of the intervals non-overlapping.

Note that intervals which only touch at a point are non-overlapping. For example, [1, 2] and [2, 3] are non-overlapping.

 

Example 1:

Input: intervals = [[1,2],[2,3],[3,4],[1,3]]
Output: 1
Explanation: [1,3] can be removed and the rest of the intervals are non-overlapping.

Example 2:

Input: intervals = [[1,2],[1,2],[1,2]]
Output: 2
Explanation: You need to remove two [1,2] to make the rest of the intervals non-overlapping.

Example 3:

Input: intervals = [[1,2],[2,3]]
Output: 0
Explanation: You don't need to remove any of the intervals since they're already non-overlapping.

Solution
var eraseOverlapIntervals = function(intervals) {
    intervals.sort((a, b) => a[1] - b[1]);

    let count = 0;
    let prevEnd = intervals[0][1];

    for (let i = 1; i < intervals.length; i++) {
        if (intervals[i][0] < prevEnd) {
            count++;
        } else {  
            prevEnd = intervals[i][1];
        }
    }

    return count;
};




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