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‎Problemset/0745-Prefix and Suffix Search/README.md

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# 745. Prefix and Suffix Search
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Design a special dictionary that searches the words in it by a prefix and a suffix.
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Implement the `WordFilter` class:
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* `WordFilter(string[] words)` Initializes the object with the `words` in the dictionary.
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* `f(string pref, string suff)` Returns *the index of the word in the dictionary*, which has the prefix `pref` and the suffix `suff`. If there is more than one valid index, return **the largest** of them. If there is no such word in the dictionary, return `-1`.
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#### Example 1:
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<pre>
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<strong>Input:</strong>
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["WordFilter", "f"]
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[[["apple"]], ["a", "e"]]
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<strong>Output:</strong>
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[null, 0]
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<strong>Explanation:</strong>
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WordFilter wordFilter = new WordFilter(["apple"]);
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wordFilter.f("a", "e"); // return 0, because the word at index 0 has prefix = "a" and suffix = "e".
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</pre>
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#### Constraints:
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* <code>1 <= words.length <= 104</sup></code>
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* `1 <= words[i].length <= 7`
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* `1 <= pref.length, suff.length <= 7`
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* `words[i]`, `pref` and `suff` consist of lowercase English letters only.
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* At most <code>10<sup>4</sup></code> calls will be made to the function `f`.
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## Solutions (Python)
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### 1. Solution
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```Python
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class WordFilter:
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def __init__(self, words: List[str]):
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self.hashmap = {}
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for i in range(len(words)):
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prefs = [words[i][:j + 1] for j in range(len(words[i]))]
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suffs = [words[i][-j - 1:] for j in range(len(words[i]))]
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for pref in prefs:
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for suff in suffs:
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self.hashmap[(pref, suff)] = i
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def f(self, pref: str, suff: str) -> int:
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return self.hashmap.get((pref, suff), -1)
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# Your WordFilter object will be instantiated and called as such:
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# obj = WordFilter(words)
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# param_1 = obj.f(pref,suff)
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```

‎Problemset/0745-Prefix and Suffix Search/README_CN.md

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# 745. 前缀和后缀搜索
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设计一个包含一些单词的特殊词典，并能够通过前缀和后缀来检索单词。
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实现 `WordFilter` 类：
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* `WordFilter(string[] words)` 使用词典中的单词 `words` 初始化对象。
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* `f(string pref, string suff)` 返回词典中具有前缀 `pref` 和后缀 `suff` 的单词的下标。如果存在不止一个满足要求的下标，返回其中 **最大的下标** 。如果不存在这样的单词，返回 `-1` 。
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#### 示例 1:
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<pre>
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<strong>输入:</strong>
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["WordFilter", "f"]
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[[["apple"]], ["a", "e"]]
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<strong>输出:</strong>
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[null, 0]
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<strong>解释:</strong>
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WordFilter wordFilter = new WordFilter(["apple"]);
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wordFilter.f("a", "e"); // 返回 0 ，因为下标为 0 的单词：前缀 prefix = "a" 且 后缀 suffix = "e" 。
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</pre>
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#### 提示:
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* <code>1 <= words.length <= 104</sup></code>
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* `1 <= words[i].length <= 7`
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* `1 <= pref.length, suff.length <= 7`
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* `words[i]`、`pref` 和 `suff` 仅由小写英文字母组成
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* 最多对函数 `f` 执行 <code>10<sup>4</sup></code> 次调用
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## 题解 (Python)
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### 1. 题解
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```Python
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class WordFilter:
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def __init__(self, words: List[str]):
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self.hashmap = {}
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for i in range(len(words)):
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prefs = [words[i][:j + 1] for j in range(len(words[i]))]
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suffs = [words[i][-j - 1:] for j in range(len(words[i]))]
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for pref in prefs:
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for suff in suffs:
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self.hashmap[(pref, suff)] = i
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def f(self, pref: str, suff: str) -> int:
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return self.hashmap.get((pref, suff), -1)
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# Your WordFilter object will be instantiated and called as such:
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# obj = WordFilter(words)
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# param_1 = obj.f(pref,suff)
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```

‎Problemset/0745-Prefix and Suffix Search/Solution.py

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class WordFilter:
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def __init__(self, words: List[str]):
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self.hashmap = {}
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for i in range(len(words)):
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prefs = [words[i][:j + 1] for j in range(len(words[i]))]
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suffs = [words[i][-j - 1:] for j in range(len(words[i]))]
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for pref in prefs:
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for suff in suffs:
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self.hashmap[(pref, suff)] = i
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def f(self, pref: str, suff: str) -> int:
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return self.hashmap.get((pref, suff), -1)
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# Your WordFilter object will be instantiated and called as such:
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# obj = WordFilter(words)
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# param_1 = obj.f(pref,suff)

‎README.md

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[740][740l] |[Delete and Earn][740] |![rs]
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[743][743l] |[Network Delay Time][743] |![rs]
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[744][744l] |[Find Smallest Letter Greater Than Target][744] |![rs]
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[745][745l] |[Prefix and Suffix Search][745] |![py]
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[746][746l] |[Min Cost Climbing Stairs][746] |![rs]
502503
[747][747l] |[Largest Number At Least Twice of Others][747] |![rs]
503504
[748][748l] |[Shortest Completing Word][748] |![py]
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[740]:Problemset/0740-Delete%20and%20Earn/README.md#740-delete-and-earn
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[743]:Problemset/0743-Network%20Delay%20Time/README.md#743-network-delay-time
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[744]:Problemset/0744-Find%20Smallest%20Letter%20Greater%20Than%20Target/README.md#744-find-smallest-letter-greater-than-target
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[745]:Problemset/0745-Prefix%20and%20Suffix%20Search/README.md#745-prefix-and-suffix-search
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[746]:Problemset/0746-Min%20Cost%20Climbing%20Stairs/README.md#746-min-cost-climbing-stairs
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[747]:Problemset/0747-Largest%20Number%20At%20Least%20Twice%20of%20Others/README.md#747-largest-number-at-least-twice-of-others
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[748]:Problemset/0748-Shortest%20Completing%20Word/README.md#748-shortest-completing-word
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[740l]:https://leetcode.com/problems/delete-and-earn/
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[743l]:https://leetcode.com/problems/network-delay-time/
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[744l]:https://leetcode.com/problems/find-smallest-letter-greater-than-target/
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[745l]:https://leetcode.com/problems/prefix-and-suffix-search/
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[746l]:https://leetcode.com/problems/min-cost-climbing-stairs/
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[747l]:https://leetcode.com/problems/largest-number-at-least-twice-of-others/
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[748l]:https://leetcode.com/problems/shortest-completing-word/

‎README_CN.md

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[740][740l] |[删除并获得点数][740] |![rs]
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[743][743l] |[网络延迟时间][743] |![rs]
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[744][744l] |[寻找比目标字母大的最小字母][744] |![rs]
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[745][745l] |[前缀和后缀搜索][745] |![py]
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[746][746l] |[使用最小花费爬楼梯][746] |![rs]
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[747][747l] |[至少是其他数字两倍的最大数][747] |![rs]
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[748][748l] |[最短完整词][748] |![py]
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[740]:Problemset/0740-Delete%20and%20Earn/README_CN.md#740-删除并获得点数
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[743]:Problemset/0743-Network%20Delay%20Time/README_CN.md#743-网络延迟时间
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[744]:Problemset/0744-Find%20Smallest%20Letter%20Greater%20Than%20Target/README_CN.md#744-寻找比目标字母大的最小字母
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[745]:Problemset/0745-Prefix%20and%20Suffix%20Search/README_CN.md#745-前缀和后缀搜索
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[746]:Problemset/0746-Min%20Cost%20Climbing%20Stairs/README_CN.md#746-使用最小花费爬楼梯
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[747]:Problemset/0747-Largest%20Number%20At%20Least%20Twice%20of%20Others/README_CN.md#747-至少是其他数字两倍的最大数
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[748]:Problemset/0748-Shortest%20Completing%20Word/README_CN.md#748-最短完整词
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[740l]:https://leetcode.cn/problems/delete-and-earn/
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[743l]:https://leetcode.cn/problems/network-delay-time/
37443746
[744l]:https://leetcode.cn/problems/find-smallest-letter-greater-than-target/
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[745l]:https://leetcode.cn/problems/prefix-and-suffix-search/
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[746l]:https://leetcode.cn/problems/min-cost-climbing-stairs/
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[747l]:https://leetcode.cn/problems/largest-number-at-least-twice-of-others/
37473750
[748l]:https://leetcode.cn/problems/shortest-completing-word/

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