Update 0435.无重叠区间.md

problems/0435.无重叠区间.md

@@ -248,20 +248,45 @@ class Solution {
 ```
 
 ### Python 
+贪心 基于左边界
 ```python
 class Solution:
     def eraseOverlapIntervals(self, intervals: List[List[int]]) -> int:
-        if len(intervals) == 0: return 0
+        if not intervals:
-        intervals.sort(key=lambda x: x[1])
+            return 0
-        count = 1 # 记录非交叉区间的个数
-        end = intervals[0][1] # 记录区间分割点
-        for i in range(1, len(intervals)):
-            if end <= intervals[i][0]:
-                count += 1
-                end = intervals[i][1]
-        return len(intervals) - count
-```
         
+        intervals.sort(key=lambda x: x[0])  # 按照左边界升序排序
+        count = 0  # 记录重叠区间数量
+        
+        for i in range(1, len(intervals)):
+            if intervals[i][0] < intervals[i - 1][1]:  # 存在重叠区间
+                intervals[i][1] = min(intervals[i - 1][1], intervals[i][1])  # 更新重叠区间的右边界
+                count += 1
+        
+        return count
+
+```
+贪心 基于左边界 把452.用最少数量的箭引爆气球代码稍做修改
+```python
+class Solution:
+    def eraseOverlapIntervals(self, intervals: List[List[int]]) -> int:
+        if not intervals:
+            return 0
+        
+        intervals.sort(key=lambda x: x[0])  # 按照左边界升序排序
+        
+        result = 1  # 不重叠区间数量，初始化为1，因为至少有一个不重叠的区间
+        
+        for i in range(1, len(intervals)):
+            if intervals[i][0] >= intervals[i - 1][1]:  # 没有重叠
+                result += 1
+            else:  # 重叠情况
+                intervals[i][1] = min(intervals[i - 1][1], intervals[i][1])  # 更新重叠区间的右边界
+        
+        return len(intervals) - result
+
+
+```
 ### Go 
 ```go
 func eraseOverlapIntervals(intervals [][]int) int {