Design a stack that supports push, pop, top, and retrieving the minimum element in constant time.<\/p>\n
Example:<\/b><\/p>\n Python<\/strong><\/p>\nMinStack minStack = new MinStack();\r\nminStack.push(-2);\r\nminStack.push(0);\r\nminStack.push(-3);\r\nminStack.getMin(); --> Returns -3.\r\nminStack.pop();\r\nminStack.top(); --> Returns 0.\r\nminStack.getMin(); --> Returns -2.<\/pre>\n
\r\nclass MinStack(object):\r\n def __init__(self):\r\n """\r\n initialize your data structure here.\r\n """\r\n self.min_stack = []\r\n self.min_num_stack = []\r\n\r\n def push(self, x):\r\n """\r\n :type x: int\r\n :rtype: void\r\n """\r\n if len(self.min_num_stack) == 0 or x <= self.min_num_stack[-1]:\r\n self.min_num_stack.append(x)\r\n self.min_stack.insert(0, x)\r\n\r\n def pop(self):\r\n """\r\n :rtype: void\r\n """\r\n if self.min_stack[0] == self.min_num_stack[-1]:\r\n self.min_num_stack.pop()\r\n del self.min_stack[0]\r\n\r\n def top(self):\r\n """\r\n :rtype: int\r\n """\r\n return self.min_stack[0]\r\n\r\n def getMin(self):\r\n """\r\n :rtype: int\r\n """\r\n return self.min_num_stack[-1]\r\n<\/pre>\n","protected":false},"excerpt":{"rendered":"