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50 lines
1.1 KiB
Markdown
50 lines
1.1 KiB
Markdown
# [150. Evaluate Reverse Polish Notation](https://leetcode.com/problems/evaluate-reverse-polish-notation/)
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## 题目
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Evaluate the value of an arithmetic expression in Reverse Polish Notation.
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Valid operators are +, -, *, /. Each operand may be an integer or another expression.
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Note:
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- Division between two integers should truncate toward zero.
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- The given RPN expression is always valid. That means the expression would always evaluate to a result and there won't be any divide by zero operation.
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Example 1:
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```c
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Input: ["2", "1", "+", "3", "*"]
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Output: 9
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Explanation: ((2 + 1) * 3) = 9
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```
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Example 2:
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```c
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Input: ["4", "13", "5", "/", "+"]
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Output: 6
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Explanation: (4 + (13 / 5)) = 6
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```
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Example 3:
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```c
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Input: ["10", "6", "9", "3", "+", "-11", "*", "/", "*", "17", "+", "5", "+"]
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Output: 22
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Explanation:
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((10 * (6 / ((9 + 3) * -11))) + 17) + 5
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= ((10 * (6 / (12 * -11))) + 17) + 5
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= ((10 * (6 / -132)) + 17) + 5
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= ((10 * 0) + 17) + 5
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= (0 + 17) + 5
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= 17 + 5
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= 22
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```
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## 题目大意
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计算逆波兰表达式。
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## 解题思路
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这道题就是经典的考察栈的知识的题目。 |