Given a list of sorted characters letters
containing only lowercase letters, and given a target letter target
, find the smallest element in the list that is larger than the given target.
Letters also wrap around. For example, if the target is target = 'z'
and letters = ['a', 'b']
, the answer is 'a'
.
Examples:
Input: letters = ["c", "f", "j"] target = "a" Output: "c" Input: letters = ["c", "f", "j"] target = "c" Output: "f" Input: letters = ["c", "f", "j"] target = "d" Output: "f" Input: letters = ["c", "f", "j"] target = "g" Output: "j" Input: letters = ["c", "f", "j"] target = "j" Output: "c" Input: letters = ["c", "f", "j"] target = "k" Output: "c"
Note:
letters
has a length in range[2, 10000]
.letters
consists of lowercase letters, and contains at least 2 unique letters.target
is a lowercase letter.
A:
一开始没有弄明白什么是wrap around. 下面这个,没有用上 list of sorted characters
class Solution { public: char nextGreatestLetter(vector<char>& letters, char target) { char largerRes ='A'; char smallerRes = 'A'; for(auto ch:letters) { if(ch>target){ if( isupper(largerRes) || ch < largerRes ) { largerRes = ch; } }else if(ch<target){ if( isupper(smallerRes) || ch < smallerRes ) { smallerRes = ch; } } } return isupper(largerRes)?smallerRes:largerRes; } };
-----------------------利用了sorted List---
class Solution { public: char nextGreatestLetter(vector<char>& letters, char target) { for(auto ch:letters) if(ch > target) return ch; return letters[0]; } };
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