个人技术分享

class Solution {
public:
    bool isPowerOfTwo(int n) {
        return n>0 &&(n & (n-1))==0;

    }
};

class Solution {
public:
    int firstUniqChar(string s) {
        unordered_map<char,int> m;
        for(char c:s)
        {
            if(m.find(c) == m.end())
            {
                m[c] = 1;
            }
            else
            {
                m[c] = -1;
            }
        }
        for(int i = 0;i < s.size();i++)
        {
            if(m[s[i]] == 1)
            {
                return i;
            }
        }
        return -1;

    }
};