[LeetCode]Count and Say

最新推荐文章于 2019-08-14 16:27:56 发布

原创最新推荐文章于 2019-08-14 16:27:56 发布 · 2.3k 阅读

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本文介绍了一种使用C++编程语言实现数位计数器算法的方法，详细解释了如何通过字符串流、循环和条件判断来构建递进的数位计数器。该算法用于生成特定模式的字符串序列，适用于数据结构、算法和编程教学场景。

class Solution {
//find the regular pattern
public:
	string countAndSay(int n) {
		// Start typing your C/C++ solution below
		// DO NOT write int main() function
		string ans("1");
		int rank = 1;
		while (rank < n)
		{
			stringstream str;
			int charCnt = 1;
			char foreChar = ans[0];
			for (int i = 1; i < ans.size(); ++i)
			{
				if(ans[i] != foreChar)
				{
					str<<charCnt<<foreChar;
					foreChar = ans[i];
					charCnt = 1;
				}
				else charCnt++;
			}
			str<<charCnt<<foreChar;
			ans = str.str();
			rank++;
		}
		return ans;
	}
};

second time

class Solution {
public:
    string countAndSay(int n) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        string num = "1";
        for(int i = 2; i <= n; ++i)
        {
            int j = 0;
            string newNum;
            while(j < num.size())
            {
                int k;
                for(k = j+1; k < num.size(); ++k)
                    if(num[k] != num[j]) break;
                newNum.push_back(k-j+'0');
                newNum.push_back(num[j]);
                j = k;
            }
            num = newNum;
        }
        return num;
    }
};