761. 特殊的二进制序列

代码实现（部分看题解）

class Solution {
    
public:
    string makeLargestSpecial(string s) {
    
        if (s.size() <= 2) return s;
        int left = 0, cnt = 0;
        vector<string> subs;
        for (int i = 0; i < s.size(); i++) {
    
            if (s[i] == '1') {
    
                cnt++;
            }
            else {
    
                cnt--;
                if (!cnt) {
    
                    // 获得1 + 从left + 1，长为i - left - 1 + 0的子串
                    subs.push_back("1" +
                    makeLargestSpecial(s.substr(left + 1, i -left - 1))
                    + "0");
                    left = i + 1;
                }
            }
        }
        sort(subs.begin(), subs.end(), greater<string>());
        return accumulate(subs.begin(), subs.end(), ""s);
    }
};