Leetcode-944 Delete Columns to Make Sorted(删除列以使之有序)

class Solution
{
    public:
        bool order(string A)
        {
            for(int i = 0; i < A.size()-1; i ++)
            {
                if(A[i]>A[i+1])
                {
                    return false;
                }
            }
            return true;
        }
        int minDeletionSize(vector<string>& A)
        {
            int indexMax = A[0].size();

            int result = 0;
            for(int i = 0; i < indexMax; i ++)
            {
                string tmp;
                for(int j = 0; j < A.size(); j ++)
                {
                    tmp += A[j][i];
                }
                if(!order(tmp))
                    result ++;
                tmp.clear();
            }
            return result;
        }
};