题目描述:
Design a stack that supports push, pop, top, and retrieving the minimum element in constant time.
- push(x) -- Push element x onto stack.
- pop() -- Removes the element on top of the stack.
- top() -- Get the top element.
- getMin() -- Retrieve ...
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Design a stack that supports push, pop, top, and retrieving the minimum element in constant time.
LeetCode 154. Find Minimum in Rotated Sorted Array II
Follow up for "Find Minimum in Rotated Sorted Array":
What if duplicates are allowed?Would this affect the run-time complexity? How and why?
Suppose a sorted array is rotated at ...
Given n points on a 2D plane, find the maximum number of points that lie on the same straight line.
平面上有n个点,找出共线的点的最大个数
很容易想到O(n^3)的解法,通过起点i,终点j枚举直线,然后枚举中间点k,依次判断k与i,j是否共线,统计最大值。
实际上,采用此题可以采用O(n^2 * log ...
Evaluate the value of an arithmetic expression in Reverse Polish Notation.
Valid operators are +, -, *, /. Each operand may be an integer or another expression.
Some examples:
["2", "1", "+", "3", "*"] -> ((2 + 1) * 3) -> 9 ...
Given an input string, reverse the string word by word.
For example,
Given s = "the sky is blue",
return "blue is sky the".
Clarification:
What constitutes a word?
A sequence of non-space characters constitutes a word.
Could the input ...