# Minimum Number of Arrows to Burst Balloons

Category

Intervals

Checkbox

Checkbox

Difficulty

Medium

Index

73

Key Ideas

The key idea to solve this problem is to sort the intervals based on their end points and then use a greedy approach to find the minimum number of arrows needed to burst all the balloons.

Problem Number

452

Problem Summary

The problem "Minimum Number of Arrows to Burst Balloons" (Problem Number: 452) is a medium-level problem in the Intervals category on LeetCode. The goal is to find the minimum number of arrows needed to burst a set of balloons, where each balloon is represented by an interval on a number line. A key pitfall in this problem is to correctly identify the overlapping intervals and efficiently determine the minimum number of arrows needed to burst all the balloons.

Solution Summary

The best solution to solve the Minimum Number of Arrows to Burst Balloons problem is as follows:
1. Sort the balloons by their end points in ascending order.
2. Initialize a variable

`end`

to the first balloon's end point.
3. Iterate through the remaining balloons.
4. If the current balloon's start point is greater than `end`

, it means a new arrow is needed. Increment the arrow count and update `end`

to the current balloon's end point.
5. If the current balloon's start point is less than or equal to `end`

, it means the arrow can burst this balloon without a new arrow. Update `end`

to the minimum of `end`

and the current balloon's end point.
6. Repeat steps 4 and 5 until all balloons are processed.
7. Return the total number of arrows used.
This solution works by greedily bursting the balloons using the minimum number of arrows. By sorting the balloons based on their end points, we can easily determine if a new arrow is needed or if an existing arrow can be used to burst multiple balloons.Tags

Array

Greedy

Sorting