leetcode 394. Decode String (medium)

版权声明：by ruohua3kou https://blog.csdn.net/ruohua3kou/article/details/88967595

看到嵌套就想到递归… 大问题化小问题

class Solution
{
  public:
	string decodeString(const string &s, int &i)
	{
		string res;
		while (i < s.length() && s[i] != ']')
		{
			if (isdigit(s[i]))
			{
				int count = 0;
				while (isdigit(s[i]) && i < s.length())
					count = 10 * count + (s[i++] - '0');
				++i; // jump over [
				string temp = decodeString(s, i);
				++i; // jump over ]
				while (count > 0)
				{
					res += temp;
					--count;
				}
			}
			else
				res += s[i++];
		}
		return res;
	}
	string decodeString(string s)
	{
		int i = 0;
		return decodeString(s, i);
	}
};