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.
注意char * 和 string的区别。string是一个和vector类，本身是有大小的。如果只
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string str;str[0] = ‘a‘;str[1] = ‘b‘; |
是无法正常改变str的。
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class
Solution {public: string countAndSay(int
n) { string re; vector <int> se; se.push_back(1); if(n == 1)return
"1"; for(int
i = 0 ; i < n-1 ;i++)se = nth(se); int
j = 0; for(int
i = 0 ; se.begin() + i != se.end() ; i++) { char
temp = se[i] + ‘0‘; re = re + temp; j++; } return
re; } vector<int> nth(vector<int> n ) { vector<int>:: iterator it; vector<int> re; it = n.begin(); for(;it != n.end();) { int
temp = *it; //cout<<temp<<endl; int
num =1; it++; while(*it == temp && it!= n.end()){it++; num++;} re.push_back(num); re.push_back(temp); } return
re; }}; |
原文：http://www.cnblogs.com/pengyu2003/p/3573876.html