随笔分类 - LeetCode
摘要：X is a good number if after rotating each digit individually by 180 degrees, we get a valid number that is different from X. A number is valid if each
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摘要：Evaluate the value of an arithmetic expression in Reverse Polish Notation. Valid operators are +, -, *, /. Each operand may be an integer or another e
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摘要：Given a binary tree, find its minimum depth. The minimum depth is the number of nodes along the shortest path from the root node down to the nearest l
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