Leetcode-5064 Remove All Adjacent Duplicates In String(删除字符串中的所有相邻重复项)

#define _for(i,a,b) for(int i = (a);i < b;i ++)

class Solution
{
    public:
        string removeDuplicates(string S)
        {
                _for(i,0,S.size()-1)
                {
                    if(S[i]==S[i+1])
                    {
                        S.erase(i,2);
                        i -= 2;
                        if(i==-2)
                            i = -1;
                    }
                    if(S.size()<=1)
                        break;
                }
            return S;
        }
};