38_外观数列.cpp

class Solution {
public:
    string countAndSay(int n) {
        // 模拟法
        string s = "1";
        for(int i = 0; i < n - 1; i++) {
            string t = "";
            for(int j = 0; j < s.size(); ) {
                int k = j + 1;
                while(k < s.size() && s[j] == s[k]) k ++;
                t += to_string(k - j) + s[j];
                j = k;
            }
            s = t;
        }
        return s;
    }
};