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Note: The lower one can cross other higher recetangle. Thus height[j] <= height[left/ right -/+ 1] 阅读全文
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Brute Force: has '*' before find last index of s and p when star found, s move forward char s not reaches end -- > p reaches end | no star NOT MATCH | 阅读全文
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Note: 1. There is a trick here: As it only gets the starting point, we can check each bound of the building. Also we have to have a "sign" to know whe 阅读全文
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Note: 1. When real index is 0. It will be only add as first element without any opeartors. 2. When the starting char of one layer is '0', it should br 阅读全文
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Note: It could be other chars in the String. Do not count as invalid parenthesis. Second try: 1. Count j until i. not exceed i. 2. Return after remove 阅读全文
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Note: 1. Scan from the small level. 2. Only take the index larger one if same digits. 阅读全文