LeetCode Count and Say

题目

The count-and-say sequence is the sequence of integers beginning as follows:
1, 11, 21, 1211, 111221, ...

1 is read off as "one 1" or 11.
11 is read off as "two 1s" or 21.
21 is read off as "one 2, then one 1" or 1211.

Given an integer n, generate the n^th sequence.

Note: The sequence of integers will be represented as a string.

直接模拟

代码：

class Solution {
public:
	string toString(int n)	//将数字转化为string
	{
		string ans;
		int radix=1;
		while(n/radix>9)
			radix*=10;
		while(radix>0)
		{
			ans.push_back('0'+n/radix);
			n%=radix;
			radix/=10;
		}
		return ans;
	}
    string countAndSay(int n) {
        string ans="1",temp;
		int i,j,k,len;
		for(i=1;i<n;i++)	//直接模拟
		{
			len=ans.size();
			j=0;
			while(j<len)
			{
				k=j+1;
				while(k<len&&ans[k]==ans[j])
					k++;
				temp+=toString(k-j);
				temp.push_back(ans[j]);
				j=k;
			}
			ans=temp;
			temp.clear();
		}
		return ans;
    }
};