LeetCode 0038 - Count and Say

Reck Zhang

发布于 2021-08-11 10:36:34

1580

发布于 2021-08-11 10:36:34

文章被收录于专栏：Reck Zhang

Count and Say

Desicription

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

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:

Input: 1
Output: "1"

Example 2:

Input: 4
Output: "1211"

Solution

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;
    }
};

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原始发表：2017-11-11，如有侵权请联系 cloudcommunity@tencent.com 删除

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