LeetCode-003无重复字符的最长子串(Longest Substring Without Repeating Characters)

class Solution {
    public int lengthOfLongestSubstring(String s) {
    	int cur=0;							//Cursor
    	int len=s.length();					//Length
    	char str[]=new char[len];			//Array
    	int letters[]=new int[128];			//Counter
    	int longest=0;						//Longest
    	int maxLetter=0;					//Index of max
    	int lettersIndex[]=new int[128];	//Index of character
    	int former=0;						//Former position if repeat
    	int letter=0;						//Ascii of letter
    	for (;cur<len;cur++)
    		str[cur]=s.charAt(cur);
    	for (cur=0;cur<len;cur++) {
    		for (int index=cur;index<len;index++) {		
    			letter=str[index];						//Letter --- str[index]-'A'
    			lettersIndex[letter]+=index;			//Sum of position, to find the former.
    			if (++letters[letter]==2) {				//Repeat!
    				maxLetter	=IntStream				//Stream
    							.range(0,letters.length)
    							.reduce((i,j)->			//Lambda expression
    									letters[i]>letters[j]?i:j)
    							.getAsInt();
    				former=lettersIndex[letter]-index;
        			longest=longest>index-cur?longest:index-cur;
        			cur=former;							//cur=former+1, cause 'c++'
    				break;
    			}
    			if (index==len-1) {						//No repeat
    				longest=longest>len-cur?longest:len-cur;
    				cur=len;							//End
    				break;
    			}
    		}
    		zeros(letters);
			zeros(lettersIndex);
    	}
        return longest;
    }
    public int[] zeros(int[] array) {for (int i=0;i<array.length-1;i++) array[i]=0; return array;}
}