diff --git a/Solution/452. Minimum Number of Arrows to Burst Balloons/452. Minimum Number of Arrows to Burst Balloons.py b/Solution/452. Minimum Number of Arrows to Burst Balloons/452. Minimum Number of Arrows to Burst Balloons.py new file mode 100644 index 0000000..0bade91 --- /dev/null +++ b/Solution/452. Minimum Number of Arrows to Burst Balloons/452. Minimum Number of Arrows to Burst Balloons.py @@ -0,0 +1,8 @@ +class Solution: + def findMinArrowShots(self, points: List[List[int]]) -> int: + ans, last = 0, -inf + for a, b in sorted(points, key=lambda x: x[1]): + if a > last: + ans += 1 + last = b + return ans \ No newline at end of file diff --git a/Solution/452. Minimum Number of Arrows to Burst Balloons/readme.md b/Solution/452. Minimum Number of Arrows to Burst Balloons/readme.md new file mode 100644 index 0000000..a098f35 --- /dev/null +++ b/Solution/452. Minimum Number of Arrows to Burst Balloons/readme.md @@ -0,0 +1,135 @@ +--- +comments: true +difficulty: Medium +edit_url: Antim +tags: + - Greedy + - Array + - Sorting +--- + + + +# [452. Minimum Number of Arrows to Burst Balloons](https://leetcode.com/problems/minimum-number-of-arrows-to-burst-balloons) + +## Description + + + +
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 <= 105points[i].length == 2-231 <= xstart < xend <= 231 - 1