LeetCode - 38.报数

 

class Solution {
public:
    string countAndSay(int n) {
        if(n==1){
            return "1";        
        }
        string s = countAndSay(n-1);
        string ret;
        
        char last = -1;
        int count = 0;
        
        for(int i=0;i<s.size();i++){
            if(last==-1){
                last = s[i];
                count = 1;
            }else if(last==s[i]){
                count++;
            }
            if(last!=s[i]){
                do{
                    ret+= ('0'+count%10);
                    count /=10;
                }while(count!=0);
                ret += last;
                last = s[i];
                count = 1;
            }
        }
        do{
            ret+= ('0'+count%10);
            count /=10;
        }while(count!=0);
        ret += last;
        return ret;
    }
};

https://leetcode-cn.com/problems/count-and-say/submissions/