leetcode刷題--459. Repeated Substring Pattern

class Solution {
public:
    bool repeatedSubstringPattern(string str) {
        vector<int> items(26,0);
        int len = str.size();
        int mid = len / 2;
        int flag = 0;
        for(int i = 0; i < mid; ++i)
        {
            flag = 0;
            string pat = str.substr(0,i + 1);
            for(int j = i + 1;j < len;)
            {
                for(int k = 0; k < i + 1; ++k)
                {
                    if(str[k] != str[j++])
                    {
                        flag = 1;
                        break;
                    }
                }
                if(flag == 1)
                    break;
            }
            if(flag == 0)
                return true;
        }
            return false;

    }
};

y一遍AC

從中間分開  然後分組和分別進行遍歷。