LeeCode Contest 62 Find Smallest Letter Greater Than Target

Weekly Contest 62 Find Smallest Letter Greater Than Target

问题描述

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’.

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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”

### 问题分析这道题是一道比较简单的问题，求以排序数组中大于目标值中的候选元素中的最小值。直接从后向前遍历，如果出现小于目标值的，说明上一个元素大于目标值。这里有一点说数组算是开始后最后连在一起了，所以没有大于目标值的，那就返回第一个元素。如果都比目标值大，自然也返回第一个元素## 代码如下``` javapublic char nextGreatestLetter(char[] letters, char target) {     for (int i = letters.length-1; i >=0; i--) {         //从后向前遍历整个数组         if(letters[i]<=target){             //如果大于target大于或等于当前的元素，说明前一个元素是符合要求的，这里需要考虑循环的问题             if(i==letters.length-1) return letters[0];             else return letters[i+1];         }     }     //如果遍历完都没有返回，就返回第一个元素     return letters[0]; }

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GitHub地址 https://github.com/yanqinghe/leetcode
CSDN博客地址 http://blog.csdn.net/yanqinghe123/article/category/7176678