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摘要： Symmetric TreeGiven a binary tree, check whether it is a mirror of itself (ie, symmetric around its center).For example, this binary tree is symmetric... 阅读全文

摘要： Balanced Binary TreeGiven a binary tree, determine if it is height-balanced.For this problem, a height-balanced binary tree is defined as a binary tre... 阅读全文

摘要： Wiggle Sort IIGiven an unsorted arraynums, reorder it such thatnums[0] nums[2] < nums[3]....Example:(1) Givennums = [1, 5, 1, 1, 6, 4], one possible ... 阅读全文