2019-08-20

JiayangWu · JiayangWu · commit d16a36a5b526 · 2019-08-20T23:39:24.000-04:00
diff --git a/0251.展开二维向量/0251-展开二维向量.py b/0251.展开二维向量/0251-展开二维向量.py
@@ -5,25 +5,23 @@ def __init__(self, v):
         :type v: List[List[int]]
         """
         self.list = []
-        for nums in v:
-            for item in nums:
-                self.list.append(item)
+        for item in v:
+            for num in item:
+                self.list.append(num)
         self.index = 0
-
+        
     def next(self):
         """
         :rtype: int
         """
         self.index += 1
         return self.list[self.index - 1]
-        
-        
 
     def hasNext(self):
         """
         :rtype: bool
         """
-        return self.index != len(self.list)
+        return self.index < len(self.list)
 
 
 # Your Vector2D object will be instantiated and called as such:
diff --git a/0252.会议室/0252-会议室.py b/0252.会议室/0252-会议室.py
@@ -4,8 +4,15 @@ def canAttendMeetings(self, intervals):
         :type intervals: List[List[int]]
         :rtype: bool
         """
-        intvs = sorted(intervals, key = lambda x: x[0])
-        for idx in range(1, len(intvs)):
-            if intvs[idx][0] < intvs[idx - 1][1]:
+        if not intervals:
+            return True
+        intervals = sorted(intervals, key = lambda x: x[0])
+        end = intervals[0][1]
+        for i in range(1, len(intervals)):
+            start = intervals[i][0]
+            
+            if end > start:
                 return False
+            end = intervals[i][1]
+            
         return True
diff --git a/0253.会议室II/0253-会议室II.py b/0253.会议室II/0253-会议室II.py
@@ -0,0 +1,21 @@
+class Solution(object):
+    def minMeetingRooms(self, intervals):
+        """
+        :type intervals: List[List[int]]
+        :rtype: int
+        """
+        if not intervals:
+            return 0
+        intervals = sorted(intervals, key = lambda x :x[1])
+        record = [0 for _ in range(intervals[-1][1] + 2)]
+        
+        for i, interval in enumerate(intervals):
+            start, end = interval[0], interval[1]
+            record[start] += 1
+            record[end] -= 1
+        
+        # print record
+        for i in range(1, len(record)):
+            record[i] += record[i - 1]
+        
+        return max(record)
