LeetCode 38.Count and Say

​​题目​​

c++

class Solution {
public:
    string a[31];
    string countAndSay(int n) {
        
         a[1]="1";
    for(int i=2;i<=30;i++)
    {
        char s1=a[i-1][0];int num=1;
        string str="";
        for(int j=1;j<a[i-1].size();j++)
        {
            if(a[i-1][j]!=a[i-1][j-1])
            {
                char x = num+'0';
                str+=x;
                str+=s1;
                
                num=1;
                s1=a[i-1][j];
                continue;
            }
            else
                num++;
        }
        char x = num+'0';
        str += x;
        str += s1;
        
        a[i]=str;
    }
        
        return a[n];
    }
};
``