longest_substring_without_repeating_characters.cpp

class Solution {
public:
    inline int lengthOfLongestSubstring(string s) {
        const int maxs = 96;
        
        int pos[maxs];
        int ans = 0;
        int cur = 0;
        int tmp;
        int length = s.length();
        int flag = length;
        
        memset(pos, -1, sizeof(pos));
        
        for (int i = length - 1; i >= 0; i --)
        {
            tmp = s[i] - 32;
            if (pos[tmp] != -1)
            {
                if (pos[tmp] > flag) {
                    cur = flag - i;
                    ans = max(cur, ans);                    
                } else {
                    flag = pos[tmp];
                    cur = flag - i;
                }
            } else {
                cur += 1;
                ans = max(cur, ans);
            }
            pos[tmp] = i;
        }
        
        return ans;
    }
};