[LeetCode] Longest Substring Without Repeating Characters

Given a string, find the length of the longest substring without repeating characters. For example, the longest substring without repeating letters for "abcabcbb" is "abc", which the length is 3. For "bbbbb" the longest substring is "b", with the length of 1.

Solution:

class Solution {
public:
    int lengthOfLongestSubstring(string s) {
        int length = s.length();
        if(length < 2) return length;
        int *dp = new int[length];        
        int maxLen = 1;
        dp[0] = 1;
        for(int i = 1;i < length;i++)
        {
            int curLen = 0;
            bool noRepeat = true;
            for(int j = i - 1;j >= i - dp[i - 1];j--)
            {
                if(s[j] == s[i])
                {
                    curLen = i - j - 1;
                    noRepeat = false;
                    break;
                }
            }
            if(noRepeat) 
                dp[i] = dp[i - 1] + 1;
            else 
                dp[i] = curLen + 1;
            maxLen = max(maxLen, dp[i]);
        }
        //cout << maxLen << endl;
        return maxLen;
    }
};
posted @ 2014-04-01 21:45  xchangcheng  阅读(214)  评论(0编辑  收藏  举报