Merge branch 'dev'

Author: Mrtj2016

solution/0042.Trapping Rain Water/Solution.py

@@ -0,0 +1,30 @@
+class Solution:
+    def trap(self, height):
+        """
+        :type height: List[int]
+        :rtype: int
+        """
+        length = len(height)
+        if length == 0 or length == 1:
+            return 0
+        slow = 0
+        fast = 1
+        total = 0
+        while fast < length:
+            # 每次更新stopPoint
+            stopPoint = fast
+            while fast < length and height[fast] <= height[slow]:
+                if height[fast] > height[stopPoint]:
+                    stopPoint = fast
+                fast += 1
+            # 越界了要回到stopPoint
+            if fast >= length:
+                fast = stopPoint
+            tmp = 0
+            bottom = min(height[slow], height[fast])
+            for i in range(slow + 1, fast):
+                tmp += bottom - height[i]
+            slow = fast
+            total += tmp
+            fast += 1
+        return total

solution/0141.Linked List Cycle/Solution.py

@@ -0,0 +1,21 @@
+# Definition for singly-linked list.
+# class ListNode(object):
+#     def __init__(self, x):
+#         self.val = x
+#         self.next = None
+
+
+class Solution(object):
+    def hasCycle(self, head):
+        """
+        :type head: ListNode
+        :rtype: bool
+        """
+        slow = fast = head
+        while fast and fast.next:
+            slow = slow.next
+            fast = fast.next.next
+            if slow == fast:
+                return True
+
+        return False

solution/0228.Summary Ranges/Solution.py

@@ -0,0 +1,32 @@
+class Solution(object):
+    def summaryRanges(self, nums):
+        """
+        :type nums: List[int]
+        :rtype: List[str]
+        """
+        length = len(nums)
+        if length == 0:
+            return []
+        ans = []
+        count = 0
+        idx = 0
+        while idx + count < length - 1:
+            if nums[idx + count] == nums[idx + count + 1] - 1:
+                count += 1
+            else:
+                string = ''
+                if count == 0:
+                    string = str(nums[idx])
+                else:
+                    string = str(nums[idx]) + "->" + str(nums[idx + count])
+                ans.append(string)
+                idx += count + 1
+                count = 0
+        # 末尾处理
+        string = ''
+        if count > 0:
+            string = str(nums[idx]) + "->" + str(nums[idx + count])
+        else:
+            string = str(nums[idx])
+        ans.append(string)
+        return ans