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标题：Permutations II通过率：25.7%难度：难Given a collection of numbers that might contain duplicates, return all possible unique permutations.For example,[1,1,2... 阅读全文
摘要：
标题：Permutations通过率：31.7%难度：中等Given a collection of numbers, return all possible permutations.For example,[1,2,3]have the following permutations:[1,2,3... 阅读全文
摘要：
题目：Generate Parentheses通过率：32.3%难度：中等Givennpairs of parentheses, write a function to generate all combinations of well-formed parentheses.For example,... 阅读全文