91 lines
1.5 KiB
Markdown
91 lines
1.5 KiB
Markdown
# Leetcode Reverse-Words-In-a-String
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#### 2022-07-12 09:10
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> ##### Algorithms:
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>
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> #algorithm #two_pointers
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>
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> ##### Data structures:
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>
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> #DS #string
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>
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> ##### Difficulty:
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>
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> #coding_problem #difficulty-easy
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>
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> ##### Additional tags:
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>
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> #leetcode
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>
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> ##### Revisions:
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>
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> N/A
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##### Related topics:
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##### Links:
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- [Link to problem](https://leetcode.com/problems/reverse-words-in-a-string-iii/)
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---
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### Problem
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Given a string `s`, reverse the order of characters in each word within a sentence while still preserving whitespace and initial word order.
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#### Examples
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**Example 1:**
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**Input:** s = "Let's take LeetCode contest"
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**Output:** "s'teL ekat edoCteeL tsetnoc"
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**Example 2:**
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**Input:** s = "God Ding"
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**Output:** "doG gniD"
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#### Constraints
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- `1 <= s.length <= 5 * 104`
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- `s` contains printable **ASCII** characters.
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- `s` does not contain any leading or trailing spaces.
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- There is **at least one** word in `s`.
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- All the words in `s` are separated by a single space.
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### Thoughts
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> [!summary]
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> This is a #two_pointers
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very easy and intuitive.
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### Solution
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```cpp
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class Solution {
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void reverse(string &s, int l, int r) {
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if (l >= r) {
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return;
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}
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swap(s[l++], s[r--]);
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reverse(s, l, r);
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}
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public:
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string reverseWords(string s) {
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int slow = 0, fast;
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for (int i = 0; i < s.size(); i++) {
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if (s[i] == ' ') {
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fast = i - 1;
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reverse(s, slow, fast);
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slow = i + 1;
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}
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}
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reverse(s, slow, s.size() - 1);
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return s;
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}
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};
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```
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