lintcode-384

class Solution {
public:
    /**
     * @param s: a string
     * @return: an integer 
     */
    int lengthOfLongestSubstring(string s) {
        // write your code here
        if(0==s.size())
            return 0;
        if(1==s.size())
            return 1;
        map<char,int> check;
        int max=INT_MIN,size=s.size(),count=0;
    
        int i=0;
        while(i<size){
            if(check[s[i]]){
                i=check[s[i]];
                check.clear();    
                if(count>max)
                    max=count;
                count=0;    
            }else{
                check[s[i]]=i+1;
                ++i;
                ++count;
            }
        }
        return max>count?max:count;
    }
};