452. 用最少数量的箭引爆气球
题目链接/文章讲解：代码随想录
视频讲解:贪心算法，判断重叠区间问题 | LeetCode：452.用最少数量的箭引爆气球_哔哩哔哩_bilibili
class Solution {public int findMinArrowShots(int[][] points) {Arrays.sort(points, new Comparator<int[]>() {public int compare(int[] o1, int[] o2) {return Integer.compare(o1[0], o2[0]);}});int count = 1;for (int i = 1; i < points.length; i++) {if (points[i][0] > points[i - 1][1]) {count++;} else {points[i][1] = Math.min(points[i][1], points[i - 1][1]);}}return count;}
}
435. 无重叠区间
题目链接/文章讲解：代码随想录
视频讲解:贪心算法，依然是判断重叠区间 | LeetCode：435.无重叠区间_哔哩哔哩_bilibili
class Solution {public int eraseOverlapIntervals(int[][] intervals) {Arrays.sort(intervals, new Comparator<int[]>() {public int compare(int[] o1, int[] o2) {return Integer.compare(o1[0], o2[0]);}});int count = 0;for (int i = 1; i < intervals.length; i++) {if (intervals[i][0] < intervals[i - 1][1]) {count++;intervals[i][1] = Math.min(intervals[i][1], intervals[i - 1][1]);}}return count;}
}
763.划分字母区间
题目链接/文章讲解：代码随想录
视频讲解:贪心算法，寻找最远的出现位置！ LeetCode：763.划分字母区间_哔哩哔哩_bilibili
class Solution {public List<Integer> partitionLabels(String s) {int[] last = new int[26];char[] charArray = s.toCharArray();// 记录每个字符最后出现的位置for (int i = 0; i < charArray.length; i++) {last[charArray[i] - 'a'] = i;}List<Integer> list = new ArrayList<>();int start = 0;int end = 0;for (int i = 0; i < charArray.length; i++) {// 更新当前分区的结束位置end = Math.max(end, last[charArray[i] - 'a']);// 如果当前位置是分区的结束位置，则记录分区长度并更新 startif (i == end) {list.add(end - start + 1);start = end + 1;}}return list;}
}