# 744 Find Smallest Letter Greater Than Target

### Problem

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:

1. letters has a length in range \[2, 10000].
2. letters consists of lowercase letters, and contains at least 2 unique letters.
3. target is a lowercase letter.

### Solutions

```java
class Solution {
    public char nextGreatestLetter(char[] letters, char target) {
        Character minInGreater = null;
        Character min = null;
        for (int i = 0; i < letters.length; i ++) {
            char c = letters[i];
            if (min == null || c < min) {
                min = c;
            }
            if (c > target && (minInGreater == null || c < minInGreater)) {
                minInGreater = c;
            }
        }
        return minInGreater == null? min:minInGreater;
    }
}
```

```java
class Solution {
    public char nextGreatestLetter(char[] letters, char target) {
        int left = 0, right = letters.length - 1;
        while (left <= right) {
            int mid = left + (right - left) / 2;
            if (letters[mid] <= target) {
                left ++;
            }
            else {
                right --;
            }
        }
        if (left == letters.length) {
            return letters[0];
        }
        return letters[left];
    }
}
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://ugopireddy.gitbook.io/leet-code-solutions/solutions-701-750/744-find-smallest-letter-greater-than-target.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.