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Problem: Non-overlapping Intervals

Medium
30 min
Understand how to solve the non-overlapping intervals problem by identifying and removing the minimum number of overlapping intervals. This lesson helps you master an efficient algorithm running in O(n log n) time and constant space, a common pattern in coding interviews.

Statement

Given an array of intervals where intervals[i] contains the half-open intervalAn interval that contains only one of its boundary elements. The “(” parenthesis denotes the exclusion of the starting point. The “]” bracket denotes the inclusion of the ending point., (starti,endi](start_{i}​, end_{i}], your task is to find the minimum number of intervals you need to remove to make the rest of the intervals non-overlapping.

Note: Two intervals (a,b](a, b] and (c,d](c, d] are considered overlapping if there exists a value xx such that a<xba < x \leq b and c<xdc < x \leq d. In other words, if there is any point within both intervals (excluding their starting points) where both intervals have values, they are considered overlapping. For example, the intervals (7,11](7, 11] and (10,12](10, 12] are overlapping, whereas the intervals (2,4](2, 4] and (4,5](4, 5] are non-overlapping.

Constraints:

  • 11 \leqintervals.length 103\leq 10^3

  • intervals[i].length ==2== 2

  • 5×104starti<endi5×104−5 \times 10^4 \leq start_{i} < end_{i} \leq 5 \times 10^4

Problem
Ask
Submissions

Problem: Non-overlapping Intervals

Medium
30 min
Understand how to solve the non-overlapping intervals problem by identifying and removing the minimum number of overlapping intervals. This lesson helps you master an efficient algorithm running in O(n log n) time and constant space, a common pattern in coding interviews.

Statement

Given an array of intervals where intervals[i] contains the half-open intervalAn interval that contains only one of its boundary elements. The “(” parenthesis denotes the exclusion of the starting point. The “]” bracket denotes the inclusion of the ending point., (starti,endi](start_{i}​, end_{i}], your task is to find the minimum number of intervals you need to remove to make the rest of the intervals non-overlapping.

Note: Two intervals (a,b](a, b] and (c,d](c, d] are considered overlapping if there exists a value xx such that a<xba < x \leq b and c<xdc < x \leq d. In other words, if there is any point within both intervals (excluding their starting points) where both intervals have values, they are considered overlapping. For example, the intervals (7,11](7, 11] and (10,12](10, 12] are overlapping, whereas the intervals (2,4](2, 4] and (4,5](4, 5] are non-overlapping.

Constraints:

  • 11 \leqintervals.length 103\leq 10^3

  • intervals[i].length ==2== 2

  • 5×104starti<endi5×104−5 \times 10^4 \leq start_{i} < end_{i} \leq 5 \times 10^4