day 12

Author: Your Name

146LRUCache.py

@@ -0,0 +1,94 @@
+class linkedNode:
+    def __init__(self, key = 0, val = 0):
+        self.key = key
+        self.val = val
+        self.next = None
+        self.prev = None
+class LRUCache(object):
+
+    def __init__(self, capacity):
+        """
+        :type capacity: int
+        """
+        self.capacity = capacity
+        self.hashmap = dict()
+        self.head = linkedNode(0, 0)
+        self.tail = linkedNode(0, 0)
+        self.head.next = self.tail
+        self.tail.prev = self.head
+        self.size = 0
+        
+        
+    def get(self, key):
+        """
+        :type key: int
+        :rtype: int
+        """
+        if key not in self.hashmap:
+            return -1
+        node = self.hashmap[key]
+        prev = node.prev
+        next = node.next
+        
+        prev.next = next
+        next.prev = prev
+        self._insert(node)
+        return node.val
+
+    def put(self, key, value):
+        """
+        :type key: int
+        :type value: int
+        :rtype: None
+        """
+        if self.size == self.capacity and key not in self.hashmap:
+            # delete tail
+            self._delete()
+        if key not in self.hashmap:
+            node = linkedNode(key, value)
+            self.hashmap[key] = node
+            self._insert(node)
+            self.size += 1
+        else:
+            node = self.hashmap[key]
+            node.val = value
+            prev = node.prev
+            next = node.next
+            
+            prev.next = next
+            next.prev = prev
+            self._insert(node)
+        return None
+            
+    def _delete(self):
+        # delete least visited element
+        toDelete = self.tail.prev
+        key = toDelete.key
+        tmp = toDelete.prev
+        tmp.next = self.tail
+        self.tail.prev = tmp
+        del self.hashmap[key]
+        self.size -= 1
+        
+    def _insert(self, node):
+        tmp = self.head.next
+        self.head.next = node
+        node.next = tmp
+        tmp.prev = node
+        node.prev = self.head
+   
+# Your LRUCache object will be instantiated and called as such:
+# obj = LRUCache(capacity)
+# param_1 = obj.get(key)
+# obj.put(key,value)
+
+lRUCache = LRUCache(2)
+print(lRUCache.get(2))
+print(lRUCache.put(2, 6))
+print(lRUCache.get(1))
+print(lRUCache.put(1, 5))
+print(lRUCache.put(1, 2))
+print(lRUCache.get(1))
+print(lRUCache.get(2))
+# [null,-1,null,-1,null,null,2,6]
+

48RotateImage.py

@@ -0,0 +1,25 @@
+class Solution(object):
+    def rotate(self, matrix):
+        """
+        :type matrix: List[List[int]]
+        :rtype: None Do not return anything, modify matrix in-place instead.
+        
+        """
+        # 1 2 3 4
+        # 4 5 6 4
+        # 7 8 9 4
+        # 4 4 4 4
+        # (0, 0) = (2, 0) (0, 2) = (0, 0) (2, 2) = (0, 2) (2, 0) = (2, 2)
+        n = len(matrix)
+        x = n // 2
+        y = n - x
+        for i in range(x):
+            for j in range(y):
+                matrix[i][j], matrix[j][~i], matrix[~i][~j], matrix[~j][i] = \
+                    matrix[~j][i], matrix[i][j], matrix[j][~i], matrix[~i][~j]
+        return matrix
+
+sol = Solution()
+res = sol.rotate([[0, 1], [2, 3]])
+print(res)
+