Given a 0-indexed string word and a character ch, reverse the segment of word that starts at index 0 and ends at the index of the first occurrence of ch (inclusive). If the character ch does not exist in word, do nothing.
- For example, if
word = "abcdefd"andch = "d", then you should reverse the segment that starts at0and ends at3(inclusive). The resulting string will be"dcbaefd".
Return the resulting string.
Example 1:
Input: word = "abcdefd", ch = "d" Output: "dcbaefd" Explanation: The first occurrence of "d" is at index 3. Reverse the part of word from 0 to 3 (inclusive), the resulting string is "dcbaefd".
Example 2:
Input: word = "xyxzxe", ch = "z" Output: "zxyxxe" Explanation: The first and only occurrence of "z" is at index 3. Reverse the part of word from 0 to 3 (inclusive), the resulting string is "zxyxxe".
Example 3:
Input: word = "abcd", ch = "z" Output: "abcd" Explanation: "z" does not exist in word. You should not do any reverse operation, the resulting string is "abcd".
Constraints:
1 <= word.length <= 250wordconsists of lowercase English letters.chis a lowercase English letter.
Solution: Brute Force
Time complexity: O(n)
Space complexity: O(n) / O(1)
C++
|
1 2 3 4 5 6 7 8 9 10 |
// Author: Huahua class Solution { public: string reversePrefix(string word, char ch) { for (size_t i = 0; i < word.size(); ++i) if (word[i] == ch) return string(rbegin(word) + word.size() - i - 1, rend(word)) + word.substr(i + 1); return word; } }; |
请尊重作者的劳动成果，转载请注明出处！花花保留对文章／视频的所有权利。
如果您喜欢这篇文章／视频，欢迎您捐赠花花。
If you like my articles / videos, donations are welcome.
Paypal
Venmo
huahualeetcode
huahualeetcode
微信打赏
Be First to Comment