744. Find Smallest letter Greater Than Target

Given a list of sorted characters letters containing only lowercase letters, and Given a target letter target , find the Smalle St element in the list is larger than the given target.

Letters also wrap around. For example, if the target was target = ‘z‘ letters = [‘a‘, ‘b‘] and, 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. lettersHave a length in range [2, 10000] .
2. lettersConsists of lowercase letters, and contains at least 2 unique letters.
3. targetis a lowercase letter.

The topic is a variant version of the binary lookup, the index of the returned value character array with the sizes to get rid of the target than all the characters.

1 CharNextgreatestletter (Char* Letters,intLetterssize,Chartarget) {2         intlow=0, high=letterssize;3          while(low<High ) {4             intmid=low+ (high-low)/2;5             if(Letters[mid]>target) High=mid;//if it's bigger than the target, go to the left.6             ElseLow=mid+1;//if it's smaller than the target, push it to the right.7         }8         /*L9 because the Etters array index range is 0-letterssize-1, when Low is greater than lettersSize-1,Ten Description Character Array there is no larger than the target character, at this time low==letterssize, the letterssize to take the remainder, One returns the first element of a character array.  A         */ -         returnletters[low%Letterssize]; -}

744. Find Smallest letter Greater Than Target