leetcode292周赛--6056. 字符串中最大的 3 位相同数字

class Solution {
public:
    string largestGoodInteger(string num) {
        
        int slowIndex = 0;
        int count = 0;
        vector ans;

        for (int fastIndex = 1; fastIndex < num.size(); fastIndex++) {

            if (num[fastIndex] != num[slowIndex]) {
                slowIndex++;
            } else {//相等的时候记录相等的个数,快指针移动
                count++;

                if (count >= 2) {//说明相等的个数大于3

                    int temp = num[slowIndex] - '0';
                    ans.push_back(temp);

                    slowIndex++;
                    count = 0;
                } else {
                    
                    if (fastIndex + 1 < num.size() && num[slowIndex] != num[fastIndex+1]) count = 0;//处理012244情况
                    
                    slowIndex++;
                }  
                
                
                

            }
        } 


        if (ans.size() == 0) return "";


        sort(ans.begin(),ans.end());

        string str1 = to_string(ans[ans.size()-1]);
        string str2 = to_string(ans[ans.size()-1]);
        string str3 = to_string(ans[ans.size()-1]);

        string str = str1 + str2 + str3;

        return str;    
    
    }
};