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题目描述： In a 2 dimensional array grid, each value grid[i][j] represents the height of a building located there. We are allowed to increase the height of 阅读全文
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题目描述： You're given strings J representing the types of stones that are jewels, and S representing the stones you have. Each character in Sis a type of 阅读全文
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英文版的LeetCode经常性登陆不上，前面都是在牛客网上做的题目，但是每道题都是只有简单的描述，没有example，对于输入细节完全不知道。 还好今天LeetCode可以登陆，以后在LeetCode上做题。 阅读全文
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题目描述： Evaluate the value of an arithmetic expression in Reverse Polish Notation. Valid operators are+,-,*,/. Each operand may be an integer or another 阅读全文
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题目描述： 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 near 阅读全文