Package g0401_0500.s0452_minimum_number_of_arrows_to_burst_balloons

Class Solution

java.lang.Object
g0401_0500.s0452_minimum_number_of_arrows_to_burst_balloons.Solution
public class Solution extends Object
452 - Minimum Number of Arrows to Burst Balloons\. Medium There are some spherical balloons taped onto a flat wall that represents the XY-plane. The balloons are represented as a 2D integer array `points` where points[i] = [xstart, xend] denotes a balloon whose **horizontal diameter** stretches between xstart and xend. You do not know the exact y-coordinates of the balloons. Arrows can be shot up **directly vertically** (in the positive y-direction) from different points along the x-axis. A balloon with xstart and xend is **burst** by an arrow shot at `x` if xstart <= x <= xend. There is **no limit** to the number of arrows that can be shot. A shot arrow keeps traveling up infinitely, bursting any balloons in its path. Given the array `points`, return _the **minimum** number of arrows that must be shot to burst all balloons_. **Example 1:** **Input:** points = \[\[10,16],[2,8],[1,6],[7,12]] **Output:** 2 **Explanation:** The balloons can be burst by 2 arrows: - Shoot an arrow at x = 6, bursting the balloons [2,8] and [1,6]. - Shoot an arrow at x = 11, bursting the balloons [10,16] and [7,12]. **Example 2:** **Input:** points = \[\[1,2],[3,4],[5,6],[7,8]] **Output:** 4 **Explanation:** One arrow needs to be shot for each balloon for a total of 4 arrows. **Example 3:** **Input:** points = \[\[1,2],[2,3],[3,4],[4,5]] **Output:** 2 **Explanation:** The balloons can be burst by 2 arrows: - Shoot an arrow at x = 2, bursting the balloons [1,2] and [2,3]. - Shoot an arrow at x = 4, bursting the balloons [3,4] and [4,5]. **Constraints:** * 1 <= points.length <= 105 * `points[i].length == 2` * -231 <= xstart < xend <= 231 - 1

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • findMinArrowShots

      public int findMinArrowShots(int[][] points)