LeetCode 0038 - Count and Say

Count and Say

Desicription

The count-and-say sequence is the sequence of integers with the first five terms as following:

代码语言：javascript复制

1.     1
2.     11
3.     21
4.     1211
5.     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 nth term of the count-and-say sequence.

Note: Each term of the sequence of integers will be represented as a string.

Example 1:

代码语言：javascript复制

Input: 1
Output: "1"

Example 2:

代码语言：javascript复制

Input: 4
Output: "1211"

Solution

代码语言：javascript复制

class Solution {
public:
    string countAndSay(int n) {
        string res = "1";
        n--;
        while(n--){
            string cur = "";
            for(int i = 0; res[i]; i  ){
                int cnt = 1;
                while(res[i 1] && res[i 1] == res[i])
                    i  , cnt  ;
                cur  = to_string(cnt)   res[i];
            }
            res = cur;
        }
        return res;
    }
};

count each integer sequence string

0 人点赞