摘要：Evaluate Reverse Polish NotationValid operators are+,-,*,/. Each operand may be an integer or another expression.Some examples: ["2", "1", "+", "3", "*"] -> ((2 + 1) * 3) -> 9 ["4", "13", "5", "/", " 阅读全文

摘要：将会陆续放出本人刷LeetCode所见到的一些比较有趣或者不会的题目的随笔。Note:You may only use constant extra space.For example,Given the following binary tree, 1 / \ 2 3 / \ \ 4 5 7After calling your function, the tree should look like: 1 -> NULL / \ 2 -> 3 -> NULL / \ ... 阅读全文