744. Find Smallest Letter Greater Than Target

/**
 * Problem: LeetCode 744 - Find Smallest Letter Greater Than Target
 * Difficulty: Easy
 * Language: Java
 * Author: CodeByTushu
 */
class Solution {
    public char nextGreatestLetter(char[] letters, char target) {
        int left = 0;
        int right = letters.length;

        // Perform upper bound binary search
        while (left < right) {
            int mid = left + (right - left) / 2;
            if (letters[mid] <= target) {
                left = mid + 1;
            } else {
                right = mid;
            }
        }

        // Wrap around to letters[0] if no character is strictly greater than target
        return letters[left % letters.length];
    }
}

"""
Problem: LeetCode 744 - Find Smallest Letter Greater Than Target
Difficulty: Easy
Language: Python
Author: CodeByTushu
"""
from typing import List

class Solution:
    def nextGreatestLetter(self, letters: List[str], target: str) -> str:
        left, right = 0, len(letters)

        while left < right:
            mid = left + (right - left) // 2
            if letters[mid] <= target:
                left = mid + 1
            else:
                right = mid

        return letters[left % len(letters)]

/**
 * Problem: LeetCode 744 - Find Smallest Letter Greater Than Target
 * Difficulty: Easy
 * Language: C++
 * Author: CodeByTushu
 */
#include <vector>

using namespace std;

class Solution {
public:
    char nextGreatestLetter(vector<char>& letters, char target) {
        int left = 0;
        int right = letters.size();

        while (left < right) {
            int mid = left + (right - left) / 2;
            if (letters[mid] <= target) {
                left = mid + 1;
            } else {
                right = mid;
            }
        }

        return letters[left % letters.size()];
    }
};

/**
 * Problem: LeetCode 744 - Find Smallest Letter Greater Than Target
 * Difficulty: Easy
 * Language: JavaScript
 * Author: CodeByTushu
 */
/**
 * @param {character[]} letters
 * @param {character} target
 * @return {character}
 */
var nextGreatestLetter = function(letters, target) {
    let left = 0;
    let right = letters.length;

    while (left < right) {
        const mid = (left + right) >> 1;
        if (letters[mid] <= target) {
            left = mid + 1;
        } else {
            right = mid;
        }
    }

    return letters[left % letters.length];
};