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 nth sequence.
Note: The sequence of integers will be represented as a string.
class Solution
{
private:
string Deal(const string& StartString)
{
if (StartString.empty())
{
return string();
}
const int SIZE = StartString.size();
stringstream Result;
int Index = 0;
int Count = 1;
for (; Index < (SIZE - 1); Index++)
{
if (StartString[Index] != StartString[Index + 1])
{
Result << Count << StartString[Index];
Count = 1;
}
else
{
Count++;
}
}
Result << Count << StartString[Index];
return Result.str();
}
public:
string countAndSay(int n)
{
string Result = "1";
while(--n)
{
Result = Deal(Result);
}
return Result;
}
};
原文：http://blog.csdn.net/sheng_ai/article/details/45722389