[贪心] leetcode 927 Three Equal Parts

class Solution {
public:
    vector<int> threeEqualParts(vector<int>& A) {
        vector<int> res;
        int nums = 0;
      
        int n = A.size();
        int zeros = 0;
        for(int i = n - 1; i >= 0;i--)
        {
            if(A[i] == 1) break;
            zeros++;
        }
        for(int i = 0;i < n;i++)
        {
            if(A[i] == 1) nums++;
        }
        if(nums == 0)
        {
            return {0, n - 1};
        }
        if(nums % 3) return {-1, -1};

        int count = nums / 3;
        string target;
                
        int i = 0;
        for(int k = 0; k < 3;k++)
        {
            string str;
            int one_nums = 0;
            int zero_nums = 0;
            for(;i < n; i++)
            {
                if(one_nums == count && zero_nums == zeros) break;
                if(A[i] == 0)
                {
                    if(one_nums == count)
                    {
                        zero_nums++;
                    }
                    if(!str.empty())
                        str.push_back(A[i]);
                }
                else if(A[i] == 1)
                {
                    if(one_nums == count)
                    {
                        return {-1, -1};
                    }
                    one_nums++;
                    str.push_back(A[i]);
                }   
            }

            if(target.empty())
            {
                target = str;
            }
            else
            {
                if(target != str) return {-1, -1};               
            }
            if(k == 0) res.push_back(i - 1);
            else if(k == 1) res.push_back(i);
        }
        
        return res;
    }
};