LeetCode题解——Count and Say

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 {
public:
string countAndSay(int n) {
string s = "1";
int count = 1;
while(count++ < n){
string t;
for(int i=0;i<s.size();i++){
int c=1;
while(i<s.size()-1 && s[i]==s[i+1] ) {i++;c++;}
t+=(c+'0');
t+=s[i];
}
s=t;
}
return s;
}
};